chenwx@chenwx ~ $ git clone https://github.com/python/cpython.git

chenwx@chenwx ~ $ cd cpython/
chenwx@chenwx ~/cpython $ ls
Doc	 Mac		  Modules  Programs    config.guess   configure.ac
Grammar  Makefile	  Objects  Python      config.log     install-sh
Include  Makefile.pre	  PC	   README.rst  config.status  pyconfig.h
LICENSE  Makefile.pre.in  PCbuild  Tools       config.sub     pyconfig.h.in
Lib	 Misc		  Parser   aclocal.m4  configure      setup.py

chenwx@chenwx ~ $ sudo apt-get build-dep python3.5

chenwx@chenwx ~ $ cd cpython/

chenwx@chenwx ~/cpython $ git co v3.6.1
HEAD is now at 69c0db5050f6... Update docs and patchlevel for 3.6.1 final

chenwx@chenwx ~/cpython $ ./configure --with-pydebug
...
configure: creating ./config.status
config.status: creating Makefile.pre
config.status: creating Modules/Setup.config
config.status: creating Misc/python.pc
config.status: creating Misc/python-config.sh
config.status: creating Modules/ld_so_aix
config.status: creating pyconfig.h
config.status: pyconfig.h is unchanged
creating Modules/Setup
creating Modules/Setup.local
creating Makefile

chenwx@chenwx ~/cpython $ make -s -j2
...
Python build finished successfully!
The necessary bits to build these optional modules were not found:
_bz2                  _lzma
To find the necessary bits, look in setup.py in detect_modules() for the module's name.

The following modules found by detect_modules() in setup.py, have been
built by the Makefile instead, as configured by the Setup files:
atexit                pwd                   time

Failed to build these modules:
_tkinter

chenwx@chenwx ~/cpython $ ll python
-rwxrwxr-x 1 chenwx chenwx 11M Mar 29 17:33 python
chenwx@chenwx ~/cpython $ ./python -V
Python 3.6.1
chenwx@chenwx ~/cpython $ ./python -VV
Python 3.6.1 (v3.6.1:69c0db5050f6, Mar 29 2017, 17:33:44)
[GCC 5.4.0 20160609]

chenwx@chenwx ~ $ which python
/usr/bin/python

chenwx@chenwx ~ $ ll /usr/bin/python
lrwxrwxrwx 1 root root 9 Dec 10  2015 /usr/bin/python -> python2.7

chenwx@chenwx ~ $ which python2
/usr/bin/python2

chenwx@chenwx ~ $ ll /usr/bin/python2
lrwxrwxrwx 1 root root 9 Dec 10  2015 /usr/bin/python2 -> python2.7

chenwx@chenwx ~ $ which python3
/usr/bin/python3

chenwx@chenwx ~ $ ll /usr/bin/python3
lrwxrwxrwx 1 root root 9 Mar 23  2016 /usr/bin/python3 -> python3.5

chenwx@chenwx ~ $ which python3m
/usr/bin/python3m

chenwx@chenwx ~ $ ll /usr/bin/python3m
lrwxrwxrwx 1 root root 10 Mar 23  2016 /usr/bin/python3m -> python3.5m

chenwx@chenwx ~ $ diff /usr/bin/python3.5 /usr/bin/python3.5m

chenwx@chenwx ~ $ ll /usr/bin/python*
lrwxrwxrwx 1 root root    9 Dec 10  2015 /usr/bin/python -> python2.7
lrwxrwxrwx 1 root root   16 Dec 10  2015 /usr/bin/python-config -> python2.7-config
lrwxrwxrwx 1 root root    9 Dec 10  2015 /usr/bin/python2 -> python2.7
lrwxrwxrwx 1 root root   16 Dec 10  2015 /usr/bin/python2-config -> python2.7-config
-rwxr-xr-x 1 root root 3.4M Nov 19 17:35 /usr/bin/python2.7
lrwxrwxrwx 1 root root   33 Nov 19 17:35 /usr/bin/python2.7-config -> x86_64-linux-gnu-python2.7-config
lrwxrwxrwx 1 root root    9 Mar 23  2016 /usr/bin/python3 -> python3.5
-rwxr-xr-x 2 root root 4.3M Nov 18 03:23 /usr/bin/python3.5
-rwxr-xr-x 2 root root 4.3M Nov 18 03:23 /usr/bin/python3.5m
lrwxrwxrwx 1 root root   10 Mar 23  2016 /usr/bin/python3m -> python3.5m

python2 [ -bBdEiOQRsStuUvVWxX3? ] [ -c command | -m module-name | script | - ] [ args ]
python3 [ -bBdEhiIOqsSuvVWx? ]    [ -c command | -m module-name | script | - ] [ args ]

chenwx@chenwx ~ $ python -V
Python 2.7.12

chenwx@chenwx ~ $ python -h
usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ...
Options and arguments (and corresponding environment variables):
-B     : don't write .py[co] files on import; also PYTHONDONTWRITEBYTECODE=x
-c cmd : program passed in as string (terminates option list)
-d     : debug output from parser; also PYTHONDEBUG=x
-E     : ignore PYTHON* environment variables (such as PYTHONPATH)
-h     : print this help message and exit (also --help)
-i     : inspect interactively after running script; forces a prompt even
         if stdin does not appear to be a terminal; also PYTHONINSPECT=x
-m mod : run library module as a script (terminates option list)
-O     : optimize generated bytecode slightly; also PYTHONOPTIMIZE=x
-OO    : remove doc-strings in addition to the -O optimizations
-R     : use a pseudo-random salt to make hash() values of various types be
         unpredictable between separate invocations of the interpreter, as
         a defense against denial-of-service attacks
-Q arg : division options: -Qold (default), -Qwarn, -Qwarnall, -Qnew
-s     : don't add user site directory to sys.path; also PYTHONNOUSERSITE
-S     : don't imply 'import site' on initialization
-t     : issue warnings about inconsistent tab usage (-tt: issue errors)
-u     : unbuffered binary stdout and stderr; also PYTHONUNBUFFERED=x
         see man page for details on internal buffering relating to '-u'
-v     : verbose (trace import statements); also PYTHONVERBOSE=x
         can be supplied multiple times to increase verbosity
-V     : print the Python version number and exit (also --version)
-W arg : warning control; arg is action:message:category:module:lineno
         also PYTHONWARNINGS=arg
-x     : skip first line of source, allowing use of non-Unix forms of #!cmd
-3     : warn about Python 3.x incompatibilities that 2to3 cannot trivially fix
file   : program read from script file
-      : program read from stdin (default; interactive mode if a tty)
arg ...: arguments passed to program in sys.argv[1:]

Other environment variables:
PYTHONSTARTUP: file executed on interactive startup (no default)
PYTHONPATH   : ':'-separated list of directories prefixed to the
               default module search path.  The result is sys.path.
PYTHONHOME   : alternate <prefix> directory (or <prefix>:<exec_prefix>).
               The default module search path uses <prefix>/pythonX.X.
PYTHONCASEOK : ignore case in 'import' statements (Windows).
PYTHONIOENCODING: Encoding[:errors] used for stdin/stdout/stderr.
PYTHONHASHSEED: if this variable is set to 'random', the effect is the same
   as specifying the -R option: a random value is used to seed the hashes of
   str, bytes and datetime objects.  It can also be set to an integer
   in the range [0,4294967295] to get hash values with a predictable seed.

chenwx@chenwx:~ $ python3 -V
Python 3.6.7

chenwx@chenwx:~ $ python3 -h
usage: python3 [option] ... [-c cmd | -m mod | file | -] [arg] ...
Options and arguments (and corresponding environment variables):
-b     : issue warnings about str(bytes_instance), str(bytearray_instance)
         and comparing bytes/bytearray with str. (-bb: issue errors)
-B     : don't write .pyc files on import; also PYTHONDONTWRITEBYTECODE=x
-c cmd : program passed in as string (terminates option list)
-d     : debug output from parser; also PYTHONDEBUG=x
-E     : ignore PYTHON* environment variables (such as PYTHONPATH)
-h     : print this help message and exit (also --help)
-i     : inspect interactively after running script; forces a prompt even
         if stdin does not appear to be a terminal; also PYTHONINSPECT=x
-I     : isolate Python from the user's environment (implies -E and -s)
-m mod : run library module as a script (terminates option list)
-O     : remove assert and __debug__-dependent statements; add .opt-1 before
         .pyc extension; also PYTHONOPTIMIZE=x
-OO    : do -O changes and also discard docstrings; add .opt-2 before
         .pyc extension
-q     : don't print version and copyright messages on interactive startup
-s     : don't add user site directory to sys.path; also PYTHONNOUSERSITE
-S     : don't imply 'import site' on initialization
-u     : force the binary I/O layers of stdout and stderr to be unbuffered;
         stdin is always buffered; text I/O layer will be line-buffered;
         also PYTHONUNBUFFERED=x
-v     : verbose (trace import statements); also PYTHONVERBOSE=x
         can be supplied multiple times to increase verbosity
-V     : print the Python version number and exit (also --version)
         when given twice, print more information about the build
-W arg : warning control; arg is action:message:category:module:lineno
         also PYTHONWARNINGS=arg
-x     : skip first line of source, allowing use of non-Unix forms of #!cmd
-X opt : set implementation-specific option
file   : program read from script file
-      : program read from stdin (default; interactive mode if a tty)
arg ...: arguments passed to program in sys.argv[1:]

Other environment variables:
PYTHONSTARTUP: file executed on interactive startup (no default)
PYTHONPATH   : ':'-separated list of directories prefixed to the
               default module search path.  The result is sys.path.
PYTHONHOME   : alternate <prefix> directory (or <prefix>:<exec_prefix>).
               The default module search path uses <prefix>/lib/pythonX.X.
PYTHONCASEOK : ignore case in 'import' statements (Windows).
PYTHONIOENCODING: Encoding[:errors] used for stdin/stdout/stderr.
PYTHONFAULTHANDLER: dump the Python traceback on fatal errors.
PYTHONHASHSEED: if this variable is set to 'random', a random value is used
   to seed the hashes of str, bytes and datetime objects.  It can also be
   set to an integer in the range [0,4294967295] to get hash values with a
   predictable seed.
PYTHONMALLOC: set the Python memory allocators and/or install debug hooks
   on Python memory allocators. Use PYTHONMALLOC=debug to install debug
   hooks.

chenwx@chenwx ~ $ man python
chenwx@chenwx ~ $ man python3

chenwx@chenwx ~ $ python -v
# installing zipimport hook
import zipimport # builtin
# installed zipimport hook
# /usr/lib/python2.7/site.pyc matches /usr/lib/python2.7/site.py
import site # precompiled from /usr/lib/python2.7/site.pyc
# /usr/lib/python2.7/os.pyc matches /usr/lib/python2.7/os.py
import os # precompiled from /usr/lib/python2.7/os.pyc
import errno # builtin
import posix # builtin
# /usr/lib/python2.7/posixpath.pyc matches /usr/lib/python2.7/posixpath.py
import posixpath # precompiled from /usr/lib/python2.7/posixpath.pyc
# /usr/lib/python2.7/stat.pyc matches /usr/lib/python2.7/stat.py
import stat # precompiled from /usr/lib/python2.7/stat.pyc
# /usr/lib/python2.7/genericpath.pyc matches /usr/lib/python2.7/genericpath.py
import genericpath # precompiled from /usr/lib/python2.7/genericpath.pyc
# /usr/lib/python2.7/warnings.pyc matches /usr/lib/python2.7/warnings.py
import warnings # precompiled from /usr/lib/python2.7/warnings.pyc
# /usr/lib/python2.7/linecache.pyc matches /usr/lib/python2.7/linecache.py
import linecache # precompiled from /usr/lib/python2.7/linecache.pyc
# /usr/lib/python2.7/types.pyc matches /usr/lib/python2.7/types.py
import types # precompiled from /usr/lib/python2.7/types.pyc
# /usr/lib/python2.7/UserDict.pyc matches /usr/lib/python2.7/UserDict.py
import UserDict # precompiled from /usr/lib/python2.7/UserDict.pyc
# /usr/lib/python2.7/_abcoll.pyc matches /usr/lib/python2.7/_abcoll.py
import _abcoll # precompiled from /usr/lib/python2.7/_abcoll.pyc
# /usr/lib/python2.7/abc.pyc matches /usr/lib/python2.7/abc.py
import abc # precompiled from /usr/lib/python2.7/abc.pyc
# /usr/lib/python2.7/_weakrefset.pyc matches /usr/lib/python2.7/_weakrefset.py
import _weakrefset # precompiled from /usr/lib/python2.7/_weakrefset.pyc
import _weakref # builtin
# /usr/lib/python2.7/copy_reg.pyc matches /usr/lib/python2.7/copy_reg.py
import copy_reg # precompiled from /usr/lib/python2.7/copy_reg.pyc
# /usr/lib/python2.7/traceback.pyc matches /usr/lib/python2.7/traceback.py
import traceback # precompiled from /usr/lib/python2.7/traceback.pyc
# /usr/lib/python2.7/sysconfig.pyc matches /usr/lib/python2.7/sysconfig.py
import sysconfig # precompiled from /usr/lib/python2.7/sysconfig.pyc
# /usr/lib/python2.7/re.pyc matches /usr/lib/python2.7/re.py
import re # precompiled from /usr/lib/python2.7/re.pyc
# /usr/lib/python2.7/sre_compile.pyc matches /usr/lib/python2.7/sre_compile.py
import sre_compile # precompiled from /usr/lib/python2.7/sre_compile.pyc
import _sre # builtin
# /usr/lib/python2.7/sre_parse.pyc matches /usr/lib/python2.7/sre_parse.py
import sre_parse # precompiled from /usr/lib/python2.7/sre_parse.pyc
# /usr/lib/python2.7/sre_constants.pyc matches /usr/lib/python2.7/sre_constants.py
import sre_constants # precompiled from /usr/lib/python2.7/sre_constants.pyc
import _locale # builtin
# /usr/lib/python2.7/_sysconfigdata.pyc matches /usr/lib/python2.7/_sysconfigdata.py
import _sysconfigdata # precompiled from /usr/lib/python2.7/_sysconfigdata.pyc
# /usr/lib/python2.7/plat-x86_64-linux-gnu/_sysconfigdata_nd.pyc matches /usr/lib/python2.7/plat-x86_64-linux-gnu/_sysconfigdata_nd.py
import _sysconfigdata_nd # precompiled from /usr/lib/python2.7/plat-x86_64-linux-gnu/_sysconfigdata_nd.pyc
# /usr/lib/python2.7/sitecustomize.pyc matches /usr/lib/python2.7/sitecustomize.py
import sitecustomize # precompiled from /usr/lib/python2.7/sitecustomize.pyc
import encodings # directory /usr/lib/python2.7/encodings
# /usr/lib/python2.7/encodings/__init__.pyc matches /usr/lib/python2.7/encodings/__init__.py
import encodings # precompiled from /usr/lib/python2.7/encodings/__init__.pyc
# /usr/lib/python2.7/codecs.pyc matches /usr/lib/python2.7/codecs.py
import codecs # precompiled from /usr/lib/python2.7/codecs.pyc
import _codecs # builtin
# /usr/lib/python2.7/encodings/aliases.pyc matches /usr/lib/python2.7/encodings/aliases.py
import encodings.aliases # precompiled from /usr/lib/python2.7/encodings/aliases.pyc
# /usr/lib/python2.7/encodings/ascii.pyc matches /usr/lib/python2.7/encodings/ascii.py
import encodings.ascii # precompiled from /usr/lib/python2.7/encodings/ascii.pyc
Python 2.7.12 (default, Nov 19 2016, 06:48:10)
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
dlopen("/usr/lib/python2.7/lib-dynload/readline.x86_64-linux-gnu.so", 2);
import readline # dynamically loaded from /usr/lib/python2.7/lib-dynload/readline.x86_64-linux-gnu.so
>>> exit()
# clear __builtin__._
# clear sys.path
# clear sys.argv
# clear sys.ps1
# clear sys.ps2
# clear sys.exitfunc
# clear sys.exc_type
# clear sys.exc_value
# clear sys.exc_traceback
# clear sys.last_type
# clear sys.last_value
# clear sys.last_traceback
# clear sys.path_hooks
# clear sys.path_importer_cache
# clear sys.meta_path
# clear sys.flags
# clear sys.float_info
# restore sys.stdin
# restore sys.stdout
# restore sys.stderr
# cleanup __main__
# cleanup[1] encodings
# cleanup[1] site
# cleanup[1] sysconfig
# cleanup[1] abc
# cleanup[1] _weakrefset
# cleanup[1] sre_constants
# cleanup[1] re
# cleanup[1] _codecs
# cleanup[1] _warnings
# cleanup[1] zipimport
# cleanup[1] _sysconfigdata
# cleanup[1] encodings.ascii
# cleanup[1] codecs
# cleanup[1] readline
# cleanup[1] _sysconfigdata_nd
# cleanup[1] _locale
# cleanup[1] sitecustomize
# cleanup[1] signal
# cleanup[1] traceback
# cleanup[1] posix
# cleanup[1] encodings.aliases
# cleanup[1] exceptions
# cleanup[1] _weakref
# cleanup[1] sre_compile
# cleanup[1] _sre
# cleanup[1] sre_parse
# cleanup[2] copy_reg
# cleanup[2] posixpath
# cleanup[2] errno
# cleanup[2] _abcoll
# cleanup[2] types
# cleanup[2] genericpath
# cleanup[2] stat
# cleanup[2] warnings
# cleanup[2] UserDict
# cleanup[2] os.path
# cleanup[2] linecache
# cleanup[2] os
# cleanup sys
# cleanup __builtin__
# cleanup ints: 19 unfreed ints
# cleanup floats

chenwx@chenwx ~ $ python3 -v
import _frozen_importlib # frozen
import _imp # builtin
import sys # builtin
import '_warnings' # <class '_frozen_importlib.BuiltinImporter'>
import '_thread' # <class '_frozen_importlib.BuiltinImporter'>
import '_weakref' # <class '_frozen_importlib.BuiltinImporter'>
import '_frozen_importlib_external' # <class '_frozen_importlib.FrozenImporter'>
import '_io' # <class '_frozen_importlib.BuiltinImporter'>
import 'marshal' # <class '_frozen_importlib.BuiltinImporter'>
import 'posix' # <class '_frozen_importlib.BuiltinImporter'>
import _thread # previously loaded ('_thread')
import '_thread' # <class '_frozen_importlib.BuiltinImporter'>
import _weakref # previously loaded ('_weakref')
import '_weakref' # <class '_frozen_importlib.BuiltinImporter'>
# installing zipimport hook
import 'zipimport' # <class '_frozen_importlib.BuiltinImporter'>
# installed zipimport hook
# /usr/lib/python3.5/encodings/__pycache__/__init__.cpython-35.pyc matches /usr/lib/python3.5/encodings/__init__.py
# code object from '/usr/lib/python3.5/encodings/__pycache__/__init__.cpython-35.pyc'
# /usr/lib/python3.5/__pycache__/codecs.cpython-35.pyc matches /usr/lib/python3.5/codecs.py
# code object from '/usr/lib/python3.5/__pycache__/codecs.cpython-35.pyc'
import '_codecs' # <class '_frozen_importlib.BuiltinImporter'>
import 'codecs' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d8456d128>
# /usr/lib/python3.5/encodings/__pycache__/aliases.cpython-35.pyc matches /usr/lib/python3.5/encodings/aliases.py
# code object from '/usr/lib/python3.5/encodings/__pycache__/aliases.cpython-35.pyc'
import 'encodings.aliases' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d844fcbe0>
import 'encodings' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d84563cf8>
# /usr/lib/python3.5/encodings/__pycache__/ascii.cpython-35.pyc matches /usr/lib/python3.5/encodings/ascii.py
# code object from '/usr/lib/python3.5/encodings/__pycache__/ascii.cpython-35.pyc'
import 'encodings.ascii' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d8450aa90>
import '_signal' # <class '_frozen_importlib.BuiltinImporter'>
# /usr/lib/python3.5/encodings/__pycache__/utf_8.cpython-35.pyc matches /usr/lib/python3.5/encodings/utf_8.py
# code object from '/usr/lib/python3.5/encodings/__pycache__/utf_8.cpython-35.pyc'
import 'encodings.utf_8' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d8450d588>
# /usr/lib/python3.5/encodings/__pycache__/latin_1.cpython-35.pyc matches /usr/lib/python3.5/encodings/latin_1.py
# code object from '/usr/lib/python3.5/encodings/__pycache__/latin_1.cpython-35.pyc'
import 'encodings.latin_1' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d8450d828>
# /usr/lib/python3.5/__pycache__/io.cpython-35.pyc matches /usr/lib/python3.5/io.py
# code object from '/usr/lib/python3.5/__pycache__/io.cpython-35.pyc'
# /usr/lib/python3.5/__pycache__/abc.cpython-35.pyc matches /usr/lib/python3.5/abc.py
# code object from '/usr/lib/python3.5/__pycache__/abc.cpython-35.pyc'
# /usr/lib/python3.5/__pycache__/_weakrefset.cpython-35.pyc matches /usr/lib/python3.5/_weakrefset.py
# code object from '/usr/lib/python3.5/__pycache__/_weakrefset.cpython-35.pyc'
import '_weakrefset' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d845124e0>
import 'abc' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d8450dcc0>
import 'io' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d8450da58>
# /usr/lib/python3.5/__pycache__/site.cpython-35.pyc matches /usr/lib/python3.5/site.py
# code object from '/usr/lib/python3.5/__pycache__/site.cpython-35.pyc'
# /usr/lib/python3.5/__pycache__/os.cpython-35.pyc matches /usr/lib/python3.5/os.py
# code object from '/usr/lib/python3.5/__pycache__/os.cpython-35.pyc'
import 'errno' # <class '_frozen_importlib.BuiltinImporter'>
# /usr/lib/python3.5/__pycache__/stat.cpython-35.pyc matches /usr/lib/python3.5/stat.py
# code object from '/usr/lib/python3.5/__pycache__/stat.cpython-35.pyc'
import '_stat' # <class '_frozen_importlib.BuiltinImporter'>
import 'stat' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d844b89e8>
# /usr/lib/python3.5/__pycache__/posixpath.cpython-35.pyc matches /usr/lib/python3.5/posixpath.py
# code object from '/usr/lib/python3.5/__pycache__/posixpath.cpython-35.pyc'
# /usr/lib/python3.5/__pycache__/genericpath.cpython-35.pyc matches /usr/lib/python3.5/genericpath.py
# code object from '/usr/lib/python3.5/__pycache__/genericpath.cpython-35.pyc'
import 'genericpath' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d844c1278>
import 'posixpath' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d844b8d30>
# /usr/lib/python3.5/__pycache__/_collections_abc.cpython-35.pyc matches /usr/lib/python3.5/_collections_abc.py
# code object from '/usr/lib/python3.5/__pycache__/_collections_abc.cpython-35.pyc'
import '_collections_abc' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d844c1908>
import 'os' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d845271d0>
# /usr/lib/python3.5/__pycache__/_sitebuiltins.cpython-35.pyc matches /usr/lib/python3.5/_sitebuiltins.py
# code object from '/usr/lib/python3.5/__pycache__/_sitebuiltins.cpython-35.pyc'
import '_sitebuiltins' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d845274a8>
# /usr/lib/python3.5/__pycache__/sysconfig.cpython-35.pyc matches /usr/lib/python3.5/sysconfig.py
# code object from '/usr/lib/python3.5/__pycache__/sysconfig.cpython-35.pyc'
import 'sysconfig' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d8447c0b8>
# /usr/lib/python3.5/__pycache__/_sysconfigdata.cpython-35.pyc matches /usr/lib/python3.5/_sysconfigdata.py
# code object from '/usr/lib/python3.5/__pycache__/_sysconfigdata.cpython-35.pyc'
# /usr/lib/python3.5/plat-x86_64-linux-gnu/__pycache__/_sysconfigdata_m.cpython-35.pyc matches /usr/lib/python3.5/plat-x86_64-linux-gnu/_sysconfigdata_m.py
# code object from '/usr/lib/python3.5/plat-x86_64-linux-gnu/__pycache__/_sysconfigdata_m.cpython-35.pyc'
import '_sysconfigdata_m' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d84481b70>
import '_sysconfigdata' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d84481978>
# /usr/lib/python3.5/__pycache__/sitecustomize.cpython-35.pyc matches /usr/lib/python3.5/sitecustomize.py
# code object from '/usr/lib/python3.5/__pycache__/sitecustomize.cpython-35.pyc'
import 'sitecustomize' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d8448fcf8>
import 'site' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d84519cc0>
Python 3.5.2 (default, Nov 23 2017, 16:37:01)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
# extension module 'readline' loaded from '/usr/lib/python3.5/lib-dynload/readline.cpython-35m-x86_64-linux-gnu.so'
# extension module 'readline' executed from '/usr/lib/python3.5/lib-dynload/readline.cpython-35m-x86_64-linux-gnu.so'
import 'readline' # <_frozen_importlib_external.ExtensionFileLoader object at 0x7f3d8449c208>
import 'atexit' # <class '_frozen_importlib.BuiltinImporter'>
# /usr/lib/python3.5/__pycache__/rlcompleter.cpython-35.pyc matches /usr/lib/python3.5/rlcompleter.py
# code object from '/usr/lib/python3.5/__pycache__/rlcompleter.cpython-35.pyc'
import 'rlcompleter' # <_frozen_importlib_external.SourceFileLoader object at 0x7f3d8449c320>
>>> exit()
# clear builtins._
# clear sys.path
# clear sys.argv
# clear sys.ps1
# clear sys.ps2
# clear sys.last_type
# clear sys.last_value
# clear sys.last_traceback
# clear sys.path_hooks
# clear sys.path_importer_cache
# clear sys.meta_path
# clear sys.__interactivehook__
# clear sys.flags
# clear sys.float_info
# restore sys.stdin
# restore sys.stdout
# restore sys.stderr
# cleanup[2] removing encodings.utf_8
# cleanup[2] removing codecs
# cleanup[2] removing encodings.ascii
# cleanup[2] removing os
# cleanup[2] removing site
# destroy site
# cleanup[2] removing posixpath
# cleanup[2] removing encodings.latin_1
# cleanup[2] removing builtins
# cleanup[2] removing _codecs
# cleanup[2] removing _sysconfigdata_m
# destroy _sysconfigdata_m
# cleanup[2] removing io
# destroy io
# cleanup[2] removing _weakrefset
# destroy _weakrefset
# cleanup[2] removing sysconfig
# destroy sysconfig
# cleanup[2] removing _stat
# cleanup[2] removing zipimport
# cleanup[2] removing readline
# cleanup[2] removing sitecustomize
# destroy sitecustomize
# cleanup[2] removing _imp
# cleanup[2] removing marshal
# cleanup[2] removing stat
# cleanup[2] removing _io
# cleanup[2] removing atexit
# cleanup[2] removing genericpath
# cleanup[2] removing _warnings
# cleanup[2] removing _weakref
# cleanup[2] removing os.path
# cleanup[2] removing errno
# cleanup[2] removing _sysconfigdata
# destroy _sysconfigdata
# cleanup[2] removing _frozen_importlib_external
# cleanup[2] removing sys
# cleanup[2] removing __main__
# cleanup[2] removing encodings.aliases
# cleanup[2] removing _thread
# cleanup[2] removing _frozen_importlib
# cleanup[2] removing rlcompleter
# destroy rlcompleter
# cleanup[2] removing encodings
# destroy encodings
# cleanup[2] removing _signal
# cleanup[2] removing abc
# destroy abc
# cleanup[2] removing _sitebuiltins
# cleanup[2] removing _collections_abc
# destroy _collections_abc
# cleanup[2] removing posix
# destroy zipimport
# destroy _signal
# destroy _sitebuiltins
# destroy posixpath
# destroy errno
# destroy _stat
# destroy genericpath
# destroy stat
# destroy os
# destroy __main__
# destroy readline
# destroy atexit
# cleanup[3] wiping encodings.utf_8
# cleanup[3] wiping codecs
# cleanup[3] wiping encodings.ascii
# cleanup[3] wiping encodings.latin_1
# cleanup[3] wiping _codecs
# cleanup[3] wiping _imp
# cleanup[3] wiping marshal
# cleanup[3] wiping _io
# cleanup[3] wiping _warnings
# cleanup[3] wiping _weakref
# cleanup[3] wiping _frozen_importlib_external
# destroy io
# destroy marshal
# cleanup[3] wiping encodings.aliases
# cleanup[3] wiping _thread
# cleanup[3] wiping _frozen_importlib
# destroy _weakref
# destroy _thread
# destroy _imp
# destroy _warnings
# destroy _frozen_importlib_external
# cleanup[3] wiping posix
# destroy posix
# cleanup[3] wiping sys
# cleanup[3] wiping builtins
# destroy _frozen_importlib

False      class      finally    is         return
None       continue   for        lambda     try
True       def        from       nonlocal   while
and        del        global     not        with
as         elif       if         or         yield
assert     else       import     pass
break      except     in         raise

chenwx@chenwx ~/cpython $ ll Lib/keyword.py
-rwxrwxr-x 1 chenwx chenwx 2.2K Mar 26 18:40 Lib/keyword.py

chenwx@chenwx ~/cpython $ python3
Python 3.5.2 (default, Nov 17 2016, 17:05:23)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.

>>> import keyword

>>> keyword.kwlist
['False', 'None', 'True', 'and', 'as', 'assert', 'break', 'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'finally', 'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass', 'raise', 'return', 'try', 'while', 'with', 'yield']

>>> print(*keyword.kwlist)
False None True and as assert break class continue def del elif else except finally for from global if import in is lambda nonlocal not or pass raise return try while with yield

>>> keyword.iskeyword("for")
True

+       -       *       **      /       //      %      @
<<      >>      &       |       ^       ~
<       >       <=      >=      ==      !=

chenwx@chenwx ~/cpython $ python3
Python 3.5.2 (default, Nov 17 2016, 17:05:23)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.

>>> import operator

>>> dir(operator)
['__abs__', '__add__', '__all__', '__and__', '__builtins__', '__cached__', '__concat__', '__contains__', '__delitem__', '__doc__', '__eq__', '__file__', '__floordiv__', '__ge__', '__getitem__', '__gt__', '__iadd__', '__iand__', '__iconcat__', '__ifloordiv__', '__ilshift__', '__imatmul__', '__imod__', '__imul__', '__index__', '__inv__', '__invert__', '__ior__', '__ipow__', '__irshift__', '__isub__', '__itruediv__', '__ixor__', '__le__', '__loader__', '__lshift__', '__lt__', '__matmul__', '__mod__', '__mul__', '__name__', '__ne__', '__neg__', '__not__', '__or__', '__package__', '__pos__', '__pow__', '__rshift__', '__setitem__', '__spec__', '__sub__', '__truediv__', '__xor__', '_abs', 'abs', 'add', 'and_', 'attrgetter', 'concat', 'contains', 'countOf', 'delitem', 'eq', 'floordiv', 'ge', 'getitem', 'gt', 'iadd', 'iand', 'iconcat', 'ifloordiv', 'ilshift', 'imatmul', 'imod', 'imul', 'index', 'indexOf', 'inv', 'invert', 'ior', 'ipow', 'irshift', 'is_', 'is_not', 'isub', 'itemgetter', 'itruediv', 'ixor', 'le', 'length_hint', 'lshift', 'lt', 'matmul', 'methodcaller', 'mod', 'mul', 'ne', 'neg', 'not_', 'or_', 'pos', 'pow', 'rshift', 'setitem', 'sub', 'truediv', 'truth', 'xor']

>>> print(*dir(operator))
__abs__ __add__ __all__ __and__ __builtins__ __cached__ __concat__ __contains__ __delitem__ __doc__ __eq__ __file__ __floordiv__ __ge__ __getitem__ __gt__ __iadd__ __iand__ __iconcat__ __ifloordiv__ __ilshift__ __imatmul__ __imod__ __imul__ __index__ __inv__ __invert__ __ior__ __ipow__ __irshift__ __isub__ __itruediv__ __ixor__ __le__ __loader__ __lshift__ __lt__ __matmul__ __mod__ __mul__ __name__ __ne__ __neg__ __not__ __or__ __package__ __pos__ __pow__ __rshift__ __setitem__ __spec__ __sub__ __truediv__ __xor__ _abs abs add and_ attrgetter concat contains countOf delitem eq floordiv ge getitem gt iadd iand iconcat ifloordiv ilshift imatmul imod imul index indexOf inv invert ior ipow irshift is_ is_not isub itemgetter itruediv ixor le length_hint lshift lt matmul methodcaller mod mul ne neg not_ or_ pos pow rshift setitem sub truediv truth xor

(       )       [       ]       {       }
,       :       .       ;       @       =       ->
+=      -=      *=      /=      //=     %=      @=
&=      |=      ^=      >>=     <<=     **=

'       "       #       \

$       ?       `

# this is the first comment
spam = 1  # and this is the second comment
          # ... and now a third!
text = "# This is not a comment because it's inside quotes."

'''
print("We are in a comment")
print("We are still in a comment")
'''
print("We are out of the comment")

^[ \t\v]*#.*?coding[:=][ \t]*([-_.a-zA-Z0-9]+)

coding[=:]\s*([-\w.]+)

#!/usr/bin/python
# -*- coding: <encoding-name> -*-

#!/usr/bin/python
# vim: set fileencoding=<encoding name> :

# -*- coding: <encoding-name> -*-

# vim: set fileencoding=<encoding name> :

>>> help(list)

>>> squares = []
>>> for x in range(10):
...     squares.append(x**2)
...
>>> squares
[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

>>> type(squares)
<class 'list'>

>>> squares = [x**2 for x in range(10)]
>>> squares
[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

>>> squares = list(map(lambda x: x**2, range(10)))
>>> squares
[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

>>> squares[0] = 10
>>> squares[1] = 11
>>> squares
[10, 11, 4, 9, 16, 25, 36, 49, 64, 81]

>>> squares.pop()
81
>>> squares
[10, 11, 4, 9, 16, 25, 36, 49, 64]

>>> squares.pop()
64
>>> squares
[10, 11, 4, 9, 16, 25, 36, 49]

>>> del squares[0]
>>> squares
[11, 4, 9, 16, 25, 36, 49]

>>> del squares[2:4]
>>> squares
[11, 4, 25, 36, 49]

>>> del squares[:]
>>> squares
[]

>>> squares = [x**2 for x in range(10)]
>>> squares
[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

>>> del squares
>>> squares
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'squares' is not defined

>>> help(tuple)

>>> t = (12345, 54321, 'hello!')    # or, t = 12345, 54321, 'hello!'
>>> t
(12345, 54321, 'hello!')
>>> t[0]
12345

>>> type(t)
<class 'tuple'>

>>> u = (t, (1, 2, 3, 4, 5))        # or, u = t, (1, 2, 3, 4, 5)
>>> u
((12345, 54321, 'hello!'), (1, 2, 3, 4, 5))

>>> v = ([1, 2, 3], [3, 2, 1])      # or, v = [1, 2, 3], [3, 2, 1]
>>> v
([1, 2, 3], [3, 2, 1])

>>> v[0] = [11, 22, 33]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'tuple' object does not support item assignment

>>> v[0][1] = 22
>>> v
([1, 22, 3], [3, 2, 1])

>>> empty = ()
>>> len(empty)
0
>>> empty
()

>>> singleton = ('hello',)          # or, singleton = 'hello',  <-- note trailing comma
>>> len(singleton)
1
>>> singleton
('hello',)

>>> t = (12345, 54321, 'hello!')    # or, t = 12345, 54321, 'hello!'
>>> t
(12345, 54321, 'hello!')

>>> x, y, z = t
>>> x
12345
>>> y
54321
>>> z
'hello!'

>>> help(set)

>>> basket = {'apple', 'orange', 'apple', 'pear', 'orange', 'banana'}
>>> print(basket)                      # show that duplicates have been removed
{'orange', 'banana', 'pear', 'apple'}
>>> basket
{'orange', 'pear', 'banana', 'apple'}

>>> type(basket)
<class 'set'>

>>> 'orange' in basket                 # fast membership testing
True
>>> 'crabgrass' in basket
False

>>> a = set('abracadabra')
>>> a                                  # unique letters in a
{'a', 'r', 'b', 'c', 'd'}

>>> b = set('alacazam')
>>> b                                  # unique letters in b
{'z', 'a', 'm', 'c', 'l'}

>>> a - b                              # letters in a but not in b
{'r', 'd', 'b'}
>>> a | b                              # letters in either a or b
{'a', 'c', 'r', 'd', 'b', 'm', 'z', 'l'}
>>> a & b                              # letters in both a and b
{'a', 'c'}
>>> a ^ b                              # letters in a or b but not both
{'r', 'd', 'b', 'm', 'z', 'l'}

>>> help(dict)

>>> tel = {}
>>> tel
{}

>>> type(tel)
<class 'dict'>

>>> tel = {'jack': 4098, 'sape': 4140}
>>> tel
{'sape': 4140, 'jack': 4098}

>>> tel = {'jack': 4098, 'sape': 4139, 'sape': 4141}
>>> tel
{'sape': 4141, 'jack': 4098}

>>> tel = {'jack': 4098, 'sape': 4139}
>>> tel
{'sape': 4139, 'jack': 4098}

>>> tel['guido'] = 4127
>>> tel
{'sape': 4139, 'guido': 4127, 'jack': 4098}

>>> tel['jack']
4098

>>> del tel['sape']
{'guido': 4127, 'jack': 4098}

>>> tel['irv'] = 4127
>>> tel
{'guido': 4127, 'irv': 4127, 'jack': 4098}

>>> list(tel.keys())
['irv', 'guido', 'jack']

>>> sorted(tel.keys())
['guido', 'irv', 'jack']

>>> 'guido' in tel
True

>>> 'jack' not in tel
False

>>> dict([('sape', 4139), ('guido', 4127), ('jack', 4098)])
{'sape': 4139, 'jack': 4098, 'guido': 4127}

>>> {x: x**2 for x in (2, 4, 6)}
{2: 4, 4: 16, 6: 36}

>>> dict(sape=4139, guido=4127, jack=4098)
{'sape': 4139, 'jack': 4098, 'guido': 4127}

>>> knights = {'gallahad': 'the pure', 'robin': 'the brave'}
>>> for k, v in knights.items():
...     print(k, v)
...
gallahad the pure
robin the brave

# Fibonacci series: the sum of two elements defines the next
a, b = 0, 1
while (b < 10)
    print(b)
    a, b = b, a+b

assert <expression> [, <expression> ]

if __debug__:
    if not <expression>: raise AssertionError

if __debug__:
    if not <expression1>: raise AssertionError(<expression2>)

>>> def initlog(*args):
...     pass   # Remember to implement this!
...

del <target_list>

return <expression_list>

yield <expr>
yield from <expr>

(yield <expr>)
(yield from <expr>)

raise [<expression] [from <expression>]]

>>> for n in range(2, 10):
...     for x in range(2, n):
...         if n % x == 0:
...             print(n, 'equals', x, '*', n//x)
...             break
...     else:
...         # loop fell through without finding a factor
...         print(n, 'is a prime number')
...
2 is a prime number
3 is a prime number
4 equals 2 * 2
5 is a prime number
6 equals 2 * 3
7 is a prime number
8 equals 2 * 4
9 equals 3 * 3

>>> for num in range(2, 10):
...     if num % 2 == 0:
...         print("Found an even number", num)
...         continue
...     print("Found a number", num)
Found an even number 2
Found a number 3
Found an even number 4
Found a number 5
Found an even number 6
Found a number 7
Found an even number 8
Found a number 9

import <module1> [as <name1>] [, <moduleN> [as <nameN>]]

from <relative_module> import  <identifier1> [as <name1>] [, <identifierN> [as <nameN>]]
from <relative_module> import (<identifier1> [as <name1>] [, <identifierN> [as <nameN>]])

from <module> import *

global <identifier1> [, <identifier2> [, <identifierN>]]

nonlocal <identifier1> [, <identifier2> [, <identifierN>]]

if <expression1>:
    <suite1>
elif <expression2>:
    <suite2>
elif <expressionM>:
    <suiteM>
else:
    <suiteN>

>>> x = int(input("Please enter an integer: "))
Please enter an integer: 42
>>> if x < 0:
...     x = 0
...     print('Negative changed to zero')
... elif x == 0:
...     print('Zero')
... elif x == 1:
...     print('Single')
... else:
...     print('More')
...
More

for <target_list> in <expression_list>:
    <suite>
else:
    <suite>

>>> for i in range(5):
...     print(i)
...
0
1
2
3
4

>>> words = ['cat', 'window', 'defenestrate']
>>> for w in words:
...     print(w, len(w))
...
('cat', 3)
('window', 6)
('defenestrate', 12)

>>> for w in words[:]:  # Loop over a slice copy of the entire list.
...     if len(w) > 6:
...         words.insert(0, w)
...
>>> words
['defenestrate', 'cat', 'window', 'defenestrate']

while <expression>:
    <suite>
else:
    <suite>

>>> # Fibonacci series: the sum of two elements defines the next
... a, b = 0, 1
>>> while b < 10:
...     print(b)
...     a, b = b, a+b
... else:
...     print(100)
...
1
1
2
3
5
8
100

>>> def fib(n):    # write Fibonacci series up to n
...     """Print a Fibonacci series up to n."""
...     a, b = 0, 1
...     while a < n:
...         print(a, end=' ')
...         a, b = b, a+b
...     print()
...
>>> # Now call the function we just defined:
... fib(2000)
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597

>>> fib
<function fib at 10042ed0>
>>> f = fib
>>> f(100)
0 1 1 2 3 5 8 13 21 34 55 89

>>> def fib2(n):  # return Fibonacci series up to n
...     """Return a list containing the Fibonacci series up to n."""
...     result = []
...     a, b = 0, 1
...     while a < n:
...         result.append(a)    # see below
...         a, b = b, a+b
...     return result
...
>>> f100 = fib2(100)    # call it
>>> f100                # write the result
[0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]

>>> def my_function():
...     """Do nothing, but document it.
...
...     No, really, it doesn't do anything.
...     """
...     pass
...
>>> print(my_function.__doc__)
Do nothing, but document it.

    No, really, it doesn't do anything.

>>> i = 5
>>> def f(arg = i):
...     print(arg)
...
>>> i = 6
>>> f()
5

>>> def f(a, L = []):
...     L.append(a)
...     return L
...
>>> print(f(1))
[1]
>>> print(f(2))
[1, 2]
>>> print(f(3))
[1, 2, 3]

>>> def f(a, L=None):
...     if L is None:
...         L = []
...     L.append(a)
...     return L
...
>>> print(f(1))
[1]
>>> print(f(2))
[2]
>>> print(f(3))
[3]

>>> def parrot(voltage, state='a stiff', action='voom', type='Norwegian Blue'):
...     print("-- This parrot wouldn't", action, end=' ')
...     print("if you put", voltage, "volts through it.")
...     print("-- Lovely plumage, the", type)
...     print("-- It's", state, "!")
...

parrot(1000)                                          # 1 positional argument
parrot(voltage=1000)                                  # 1 keyword argument
parrot(voltage=1000000, action='VOOOOOM')             # 2 keyword arguments
parrot(action='VOOOOOM', voltage=1000000)             # 2 keyword arguments
parrot('a million', 'bereft of life', 'jump')         # 3 positional arguments
parrot('a thousand', state='pushing up the daisies')  # 1 positional, 1 keyword

def write_multiple_items(file, separator, *args):
    file.write(separator.join(args))

>>> def concat(*args, sep="/"):
...     return sep.join(args)
...
>>> concat("earth", "mars", "venus")            # sep = "/" in this case
'earth/mars/venus'
>>> concat("earth", "mars", "venus", sep=".")   # sep = "." in this case
'earth.mars.venus'

>>> list(range(3, 6))        # normal call with separate arguments
[3, 4, 5]
>>> args = [3, 6]
>>> list(range(*args))       # call with arguments unpacked from a list
[3, 4, 5]

>>> def parrot(voltage, state='a stiff', action='voom'):
...     print("-- This parrot wouldn't", action, end=' ')
...     print("if you put", voltage, "volts through it.", end=' ')
...     print("E's", state, "!")
...
>>> d = {"voltage": "four million", "state": "bleedin' demised", "action": "VOOM"}
>>> parrot(**d)
-- This parrot wouldn't VOOM if you put four million volts through it. E's bleedin' demised !

>>> def make_incrementor(n):
...     return lambda x: x + n
...
>>> f = make_incrementor(42)
>>> f(0)
42
>>> f(1)
43

>>> pairs = [(1, 'one'), (2, 'two'), (3, 'three'), (4, 'four')]
>>> pairs.sort(key=lambda pair: pair[1])
>>> pairs
[(4, 'four'), (1, 'one'), (3, 'three'), (2, 'two')]

>>> def f(ham: str, eggs: str = 'eggs') -> str:
...     print("Annotations:", f.__annotations__)
...     print("Arguments:", ham, eggs)
...     return ham + ' and ' + eggs
...
>>> f('spam')
Annotations: {'ham': <class 'str'>, 'return': <class 'str'>, 'eggs': <class 'str'>}
Arguments: spam eggs
'spam and eggs'

# Fibonacci numbers module

def fib(n):    # write Fibonacci series up to n
    a, b = 0, 1
    while b < n:
        print(b, end=' ')
        a, b = b, a+b
    print()

def fib2(n):   # return Fibonacci series up to n
    result = []
    a, b = 0, 1
    while b < n:
        result.append(b)
        a, b = b, a+b
    return result

>>> import fibo

>>> fibo.fib(1000)
1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987
>>> fibo.fib2(100)
[1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]

>>> fibo.__name__
'fibo'

>>> fib = fibo.fib
>>> fib(500)
1 1 2 3 5 8 13 21 34 55 89 144 233 377

>>> from fibo import fib, fib2
>>> fib(500)
1 1 2 3 5 8 13 21 34 55 89 144 233 377

>>> from fibo import *
>>> fib(500)
1 1 2 3 5 8 13 21 34 55 89 144 233 377

python fibo.py <arguments>

if __name__ == "__main__":
    import sys
    fib(int(sys.argv[1]))

$ python fibo.py 50
1 1 2 3 5 8 13 21 34

sound/                          # Top-level package
      __init__.py               # Initialize the sound package
      formats/                  # Subpackage for file format conversions
              __init__.py
              wavread.py
              wavwrite.py
              aiffread.py
              aiffwrite.py
              auread.py
              auwrite.py
              ...
      effects/                  # Subpackage for sound effects
              __init__.py
              echo.py
              surround.py
              reverse.py
              ...
      filters/                  # Subpackage for filters
              __init__.py
              equalizer.py
              vocoder.py
              karaoke.py
              ...

import sound.effects.echo

sound.effects.echo.echofilter(input, output, delay=0.7, atten=4)

from sound.effects import echo

echo.echofilter(input, output, delay=0.7, atten=4)

from sound.effects.echo import echofilter

echofilter(input, output, delay=0.7, atten=4)

__all__ = ["echo", "surround", "reverse"]

>>> dir()
['__builtins__', '__doc__', '__name__', '__package__']
>>>
>>> import sys
>>> dir(sys)
['__displayhook__', '__doc__', '__egginsert', '__excepthook__', '__name__', '__package__', '__plen', '__stderr__', '__stdin__', '__stdout__', '_clear_type_cache', '_current_frames', '_getframe', '_mercurial', 'api_version', 'argv', 'builtin_module_names', 'byteorder', 'call_tracing', 'callstats', 'copyright', 'displayhook', 'dont_write_bytecode', 'exc_clear', 'exc_info', 'exc_type', 'excepthook', 'exec_prefix', 'executable', 'exit', 'exitfunc', 'flags', 'float_info', 'float_repr_style', 'getcheckinterval', 'getdefaultencoding', 'getdlopenflags', 'getfilesystemencoding', 'getprofile', 'getrecursionlimit', 'getrefcount', 'getsizeof', 'gettrace', 'hexversion', 'long_info', 'maxint', 'maxsize', 'maxunicode', 'meta_path', 'modules', 'path', 'path_hooks', 'path_importer_cache', 'platform', 'prefix', 'ps1', 'ps2', 'py3kwarning', 'setcheckinterval', 'setdlopenflags', 'setprofile', 'setrecursionlimit', 'settrace', 'stderr', 'stdin', 'stdout', 'subversion', 'version', 'version_info', 'warnoptions']
>>>
>>> print(sys.version)
3.5.0 (default, Dec 21 2015, 22:50:16)
[GCC 4.8.2]

>>> import builtins
>>> dir(builtins)
['ArithmeticError', 'AssertionError', 'AttributeError', 'BaseException', 'BlockingIOError', 'BrokenPipeError', 'BufferError', 'BytesWarning', 'ChildProcessError', 'ConnectionAbortedError', 'ConnectionError', 'ConnectionRefusedError', 'ConnectionResetError', 'DeprecationWarning', 'EOFError', 'Ellipsis', 'EnvironmentError', 'Exception', 'False', 'FileExistsError', 'FileNotFoundError', 'FloatingPointError', 'FutureWarning', 'GeneratorExit', 'IOError', 'ImportError', 'ImportWarning', 'IndentationError', 'IndexError', 'InterruptedError', 'IsADirectoryError', 'KeyError', 'KeyboardInterrupt', 'LookupError', 'MemoryError', 'NameError', 'None', 'NotADirectoryError', 'NotImplemented', 'NotImplementedError', 'OSError', 'OverflowError', 'PendingDeprecationWarning', 'PermissionError', 'ProcessLookupError', 'RecursionError', 'ReferenceError', 'ResourceWarning', 'RuntimeError', 'RuntimeWarning', 'StopAsyncIteration', 'StopIteration', 'SyntaxError', 'SyntaxWarning', 'SystemError', 'SystemExit', 'TabError', 'TimeoutError', 'True', 'TypeError', 'UnboundLocalError', 'UnicodeDecodeError', 'UnicodeEncodeError', 'UnicodeError', 'UnicodeTranslateError', 'UnicodeWarning', 'UserWarning', 'ValueError', 'Warning', 'ZeroDivisionError', '__build_class__', '__debug__', '__doc__', '__import__', '__loader__', '__name__', '__package__', '__spec__', 'abs', 'all', 'any', 'ascii', 'bin', 'bool', 'bytearray', 'bytes', 'callable', 'chr', 'classmethod', 'compile', 'complex', 'copyright', 'credits', 'delattr', 'dict', 'dir', 'divmod', 'enumerate', 'eval', 'exec', 'exit', 'filter', 'float', 'format', 'frozenset', 'getattr', 'globals', 'hasattr', 'hash', 'help', 'hex', 'id', 'input', 'int', 'isinstance', 'issubclass', 'iter', 'len', 'license', 'list', 'locals', 'map', 'max', 'memoryview', 'min', 'next', 'object', 'oct', 'open', 'ord', 'pow', 'print', 'property', 'quit', 'range', 'repr', 'reversed', 'round', 'set', 'setattr', 'slice', 'sorted', 'staticmethod', 'str', 'sum', 'super', 'tuple', 'type', 'vars', 'zip']

>>> while True print('Hello world')
  File "<stdin>", line 1
    while True print('Hello world')
                   ^
SyntaxError: invalid syntax

>>> 1/0
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ZeroDivisionError: division by zero

>>> while True:
...     try:
...         x = int(input("Please enter a number: "))
...         break
...     except ValueError:
...         print("Oops!  That was no valid number.  Try again...")
...
Please enter a number: abc
Oops!  That was no valid number.  Try again...
Please enter a number: 100

... except (RuntimeError, TypeError, NameError):
...     pass

import sys

try:
    f = open('myfile.txt')
    s = f.readline()
    i = int(s.strip())
except OSError as err:    # the except clause may specify a variable after the exception name
    print("OS error: {0}".format(err))
except ValueError:
    print("Could not convert data to an integer.")
except:
    print("Unexpected error:", sys.exc_info()[0])
    raise

for arg in sys.argv[1:]:
    try:
        f = open(arg, 'r')
    except OSError:
        print('cannot open', arg)
    else:
        print(arg, 'has', len(f.readlines()), 'lines')
        f.close()

def this_fails():
    x = 1/0

try:
    this_fails()
except ZeroDivisionError as err:
    print('Handling run-time error:', err)

>>> try:
...     raise KeyboardInterrupt
... finally:
...     print('Goodbye, world!')
...
Goodbye, world!
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
KeyboardInterrupt

>>> def divide(x, y):
...     try:
...         result = x / y
...     except ZeroDivisionError:
...         print("division by zero!")
...     else:
...         print("result is", result)
...     finally:
...         print("executing finally clause")
...
>>> divide(2, 1)
result is 2.0
executing finally clause
>>>
>>> divide(2, 0)
division by zero!
executing finally clause
>>>
>>> divide("2", "1")
executing finally clause
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 3, in divide
TypeError: unsupported operand type(s) for /: 'str' and 'str'

try:
    raise NameError('HiThere')
except NameError:
    print('An exception flew by!')
    raise

>>> help(Exception)

Help on class Exception in module builtins:

class Exception(BaseException)
 |  Common base class for all non-exit exceptions.
 |  
 |  Method resolution order:
 |      Exception
 |      BaseException
 |      object
 |  
 |  Methods defined here:
 |  
 |  __init__(self, /, *args, **kwargs)
 |      Initialize self.  See help(type(self)) for accurate signature.
 |  
 |  __new__(*args, **kwargs) from builtins.type
 |      Create and return a new object.  See help(type) for accurate signature.
 |  
 |  ----------------------------------------------------------------------
 |  Methods inherited from BaseException:
 |  
 |  __delattr__(self, name, /)
 |      Implement delattr(self, name).
 |  
 |  __getattribute__(self, name, /)
 |      Return getattr(self, name).
 |  
 |  __reduce__(...)
 |      helper for pickle
 |  
 |  __repr__(self, /)
 |      Return repr(self).
 |  
 |  __setattr__(self, name, value, /)
 |      Implement setattr(self, name, value).
 |  
 |  __setstate__(...)
 |  
 |  __str__(self, /)
 |      Return str(self).
 |  
 |  with_traceback(...)
 |      Exception.with_traceback(tb) --
 |      set self.__traceback__ to tb and return self.
 |  
 |  ----------------------------------------------------------------------
 |  Data descriptors inherited from BaseException:
 |  
 |  __cause__
 |      exception cause
 |  
 |  __context__
 |      exception context
 |  
 |  __dict__
 |  
 |  __suppress_context__
 |  
 |  __traceback__
 |  
 |  args

>>> import builtins
>>> dir(builtins)
['ArithmeticError', 'AssertionError', 'AttributeError', 'BaseException', 'BlockingIOError', 'BrokenPipeError', 'BufferError', 'BytesWarning', 'ChildProcessError', 'ConnectionAbortedError', 'ConnectionError', 'ConnectionRefusedError', 'ConnectionResetError', 'DeprecationWarning', 'EOFError', 'Ellipsis', 'EnvironmentError', 'Exception', 'False', 'FileExistsError', 'FileNotFoundError', 'FloatingPointError', 'FutureWarning', 'GeneratorExit', 'IOError', 'ImportError', 'ImportWarning', 'IndentationError', 'IndexError', 'InterruptedError', 'IsADirectoryError', 'KeyError', 'KeyboardInterrupt', 'LookupError', 'MemoryError', 'NameError', 'None', 'NotADirectoryError', 'NotImplemented', 'NotImplementedError', 'OSError', 'OverflowError', 'PendingDeprecationWarning', 'PermissionError', 'ProcessLookupError', 'RecursionError', 'ReferenceError', 'ResourceWarning', 'RuntimeError', 'RuntimeWarning', 'StopAsyncIteration', 'StopIteration', 'SyntaxError', 'SyntaxWarning', 'SystemError', 'SystemExit', 'TabError', 'TimeoutError', 'True', 'TypeError', 'UnboundLocalError', 'UnicodeDecodeError', 'UnicodeEncodeError', 'UnicodeError', 'UnicodeTranslateError', 'UnicodeWarning', 'UserWarning', 'ValueError', 'Warning', 'ZeroDivisionError', '__build_class__', '__debug__', '__doc__', '__import__', '__loader__', '__name__', '__package__', '__spec__', 'abs', 'all', 'any', 'ascii', 'bin', 'bool', 'bytearray', 'bytes', 'callable', 'chr', 'classmethod', 'compile', 'complex', 'copyright', 'credits', 'delattr', 'dict', 'dir', 'divmod', 'enumerate', 'eval', 'exec', 'exit', 'filter', 'float', 'format', 'frozenset', 'getattr', 'globals', 'hasattr', 'hash', 'help', 'hex', 'id', 'input', 'int', 'isinstance', 'issubclass', 'iter', 'len', 'license', 'list', 'locals', 'map', 'max', 'memoryview', 'min', 'next', 'object', 'oct', 'open', 'ord', 'pow', 'print', 'property', 'quit', 'range', 'repr', 'reversed', 'round', 'set', 'setattr', 'slice', 'sorted', 'staticmethod', 'str', 'sum', 'super', 'tuple', 'type', 'vars', 'zip']

class ClassName:
    <statement-1>
    ...
    <statement-N>

>>> class MyClass:
...     '''A simple example class'''
...     def __init__(self, var):
...         self.i = var
...     def f(self):
...         return "Hello world"
...     i = 123
...
>>>
>>> help(MyClass)
Help on class MyClass in module __main__:

class MyClass(builtins.object)
 |  A simple example class
 |  
 |  Methods defined here:
 |  
 |  __init__(self, var)
 |      Initialize self.  See help(type(self)) for accurate signature.
 |  
 |  f(self)
 |  
 |  ----------------------------------------------------------------------
 |  Data descriptors defined here:
 |  
 |  __dict__
 |      dictionary for instance variables (if defined)
 |  
 |  __weakref__
 |      list of weak references to the object (if defined)
 |  
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |  
 |  i = 123

>>> class Dog:
...     kind = 'canine'         # class variable shared by all instances
...     def __init__(self, name):
...         self.name = name    # instance variable unique to each instance
...
>>> d = Dog('Fido')
>>> e = Dog('Buddy')
>>> d.kind                      # shared by all dogs
'canine'
>>> e.kind                      # shared by all dogs
'canine'
>>> d.name                      # unique to d
'Fido'
>>> e.name                      # unique to e
'Buddy'

class DerivedClassName(BaseClassName):
    <statement-1>
    ...
    <statement-N>

class DerivedClassName(Base1, Base2, Base3):
    <statement-1>
    ...
    <statement-N>

class Mapping:
    def __init__(self, iterable):
        self.items_list = []
        self.__update(iterable)

    def update(self, iterable):
        for item in iterable:
            self.items_list.append(item)

    __update = update   # private copy of original update() method

class MappingSubclass(Mapping):
    def update(self, keys, values):
        # provides new signature for update()
        # but does not break __init__()
        for item in zip(keys, values):
            self.items_list.append(item)

for element in [1, 2, 3]:
    print(element)
for element in (1, 2, 3):
    print(element)
for key in {'one':1, 'two':2}:
    print(key)
for char in "123":
    print(char)
for line in open("myfile.txt"):
    print(line, end='')

>>> s = 'abc'
>>> it = iter(s)
>>> it
<iterator object at 0x00A1DB50>
>>> next(it)
'a'
>>> next(it)
'b'
>>> next(it)
'c'
>>> next(it)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
    next(it)
StopIteration

class Reverse:
    """Iterator for looping over a sequence backwards."""
    def __init__(self, data):
        self.data = data
        self.index = len(data)

    def __iter__(self):
        return self

    def __next__(self):
        if self.index == 0:
            raise StopIteration
        self.index = self.index - 1
        return self.data[self.index]

>>> rev = Reverse('spam')
>>> iter(rev)
<__main__.Reverse object at 0x00A1DB50>
>>> for char in rev:
...     print(char)
...
m
a
p
s

Help on built-in function iter in module builtins:

iter(...)
    iter(iterable) -> iterator
    iter(callable, sentinel) -> iterator

    Get an iterator from an object.  In the first form, the argument must
    supply its own iterator, or be a sequence.
    In the second form, the callable is called until it returns the sentinel.

Help on built-in function next in module builtins:

next(...)
    next(iterator[, default])

    Return the next item from the iterator. If default is given and the iterator
    is exhausted, it is returned instead of raising StopIteration.

def reverse(data):
    for index in range(len(data)-1, -1, -1):
        yield data[index]

>>> for char in reverse('golf'):
...     print(char)
...
f
l
o
g

chenwx@chenwx:~ $ python3
Python 3.6.8 (default, Jan 14 2019, 11:02:34) 
[GCC 8.0.1 20180414 (experimental) [trunk revision 259383]] on linux
Type "help", "copyright", "credits" or "license" for more information.

>>> dir(__builtins__)
['ArithmeticError', 'AssertionError', 'AttributeError', 'BaseException', 'BlockingIOError', 'BrokenPipeError', 'BufferError', 'BytesWarning', 'ChildProcessError', 'ConnectionAbortedError', 'ConnectionError', 'ConnectionRefusedError', 'ConnectionResetError', 'DeprecationWarning', 'EOFError', 'Ellipsis', 'EnvironmentError', 'Exception', 'False', 'FileExistsError', 'FileNotFoundError', 'FloatingPointError', 'FutureWarning', 'GeneratorExit', 'IOError', 'ImportError', 'ImportWarning', 'IndentationError', 'IndexError', 'InterruptedError', 'IsADirectoryError', 'KeyError', 'KeyboardInterrupt', 'LookupError', 'MemoryError', 'ModuleNotFoundError', 'NameError', 'None', 'NotADirectoryError', 'NotImplemented', 'NotImplementedError', 'OSError', 'OverflowError', 'PendingDeprecationWarning', 'PermissionError', 'ProcessLookupError', 'RecursionError', 'ReferenceError', 'ResourceWarning', 'RuntimeError', 'RuntimeWarning', 'StopAsyncIteration', 'StopIteration', 'SyntaxError', 'SyntaxWarning', 'SystemError', 'SystemExit', 'TabError', 'TimeoutError', 'True', 'TypeError', 'UnboundLocalError', 'UnicodeDecodeError', 'UnicodeEncodeError', 'UnicodeError', 'UnicodeTranslateError', 'UnicodeWarning', 'UserWarning', 'ValueError', 'Warning', 'ZeroDivisionError', '__build_class__', '__debug__', '__doc__', '__import__', '__loader__', '__name__', '__package__', '__spec__', 'abs', 'all', 'any', 'ascii', 'bin', 'bool', 'bytearray', 'bytes', 'callable', 'chr', 'classmethod', 'compile', 'complex', 'copyright', 'credits', 'delattr', 'dict', 'dir', 'divmod', 'enumerate', 'eval', 'exec', 'exit', 'filter', 'float', 'format', 'frozenset', 'getattr', 'globals', 'hasattr', 'hash', 'help', 'hex', 'id', 'input', 'int', 'isinstance', 'issubclass', 'iter', 'len', 'license', 'list', 'locals', 'map', 'max', 'memoryview', 'min', 'next', 'object', 'oct', 'open', 'ord', 'pow', 'print', 'property', 'quit', 'range', 'repr', 'reversed', 'round', 'set', 'setattr', 'slice', 'sorted', 'staticmethod', 'str', 'sum', 'super', 'tuple', 'type', 'vars', 'zip']

>>> import builtins
>>> dir(builtins)
['ArithmeticError', 'AssertionError', 'AttributeError', 'BaseException', 'BlockingIOError', 'BrokenPipeError', 'BufferError', 'BytesWarning', 'ChildProcessError', 'ConnectionAbortedError', 'ConnectionError', 'ConnectionRefusedError', 'ConnectionResetError', 'DeprecationWarning', 'EOFError', 'Ellipsis', 'EnvironmentError', 'Exception', 'False', 'FileExistsError', 'FileNotFoundError', 'FloatingPointError', 'FutureWarning', 'GeneratorExit', 'IOError', 'ImportError', 'ImportWarning', 'IndentationError', 'IndexError', 'InterruptedError', 'IsADirectoryError', 'KeyError', 'KeyboardInterrupt', 'LookupError', 'MemoryError', 'ModuleNotFoundError', 'NameError', 'None', 'NotADirectoryError', 'NotImplemented', 'NotImplementedError', 'OSError', 'OverflowError', 'PendingDeprecationWarning', 'PermissionError', 'ProcessLookupError', 'RecursionError', 'ReferenceError', 'ResourceWarning', 'RuntimeError', 'RuntimeWarning', 'StopAsyncIteration', 'StopIteration', 'SyntaxError', 'SyntaxWarning', 'SystemError', 'SystemExit', 'TabError', 'TimeoutError', 'True', 'TypeError', 'UnboundLocalError', 'UnicodeDecodeError', 'UnicodeEncodeError', 'UnicodeError', 'UnicodeTranslateError', 'UnicodeWarning', 'UserWarning', 'ValueError', 'Warning', 'ZeroDivisionError', '_', '__build_class__', '__debug__', '__doc__', '__import__', '__loader__', '__name__', '__package__', '__spec__', 'abs', 'all', 'any', 'ascii', 'bin', 'bool', 'bytearray', 'bytes', 'callable', 'chr', 'classmethod', 'compile', 'complex', 'copyright', 'credits', 'delattr', 'dict', 'dir', 'divmod', 'enumerate', 'eval', 'exec', 'exit', 'filter', 'float', 'format', 'frozenset', 'getattr', 'globals', 'hasattr', 'hash', 'help', 'hex', 'id', 'input', 'int', 'isinstance', 'issubclass', 'iter', 'len', 'license', 'list', 'locals', 'map', 'max', 'memoryview', 'min', 'next', 'object', 'oct', 'open', 'ord', 'pow', 'print', 'property', 'quit', 'range', 'repr', 'reversed', 'round', 'set', 'setattr', 'slice', 'sorted', 'staticmethod', 'str', 'sum', 'super', 'tuple', 'type', 'vars', 'zip']

abs()
all()
any()
ascii()
bin()
bool()
bytearray()
bytes()
callable()
chr()
classmethod()
compile()
complex()
delattr()
dict()
dir()
divmod()
enumerate()
eval()
exec()
filter()
float()
format()
frozenset()
getattr()
globals()
hasattr()
hash()
help()
hex()
id()
input()
int()
isinstance()
issubclass()
iter()
len()
list()
locals()
map()
max()
memoryview()
min()
next()
object()
oct()
open()
ord()
pow()
print()
property()
range()
repr()
reversed()
round()
set()
setattr()
slice()
sorted()
staticmethod()
str()
sum()
super()
tuple()
type()
vars()
zip()
__import__()

>>> help(abs)

Help on built-in function abs in module builtins:

abs(x, /)
    Return the absolute value of the argument.

BaseException
 +-- SystemExit
 +-- KeyboardInterrupt
 +-- GeneratorExit
 +-- Exception
      +-- StopIteration
      +-- StopAsyncIteration
      +-- ArithmeticError
      |    +-- FloatingPointError
      |    +-- OverflowError
      |    +-- ZeroDivisionError
      +-- AssertionError
      +-- AttributeError
      +-- BufferError
      +-- EOFError
      +-- ImportError
           +-- ModuleNotFoundError
      +-- LookupError
      |    +-- IndexError
      |    +-- KeyError
      +-- MemoryError
      +-- NameError
      |    +-- UnboundLocalError
      +-- OSError
      |    +-- BlockingIOError
      |    +-- ChildProcessError
      |    +-- ConnectionError
      |    |    +-- BrokenPipeError
      |    |    +-- ConnectionAbortedError
      |    |    +-- ConnectionRefusedError
      |    |    +-- ConnectionResetError
      |    +-- FileExistsError
      |    +-- FileNotFoundError
      |    +-- InterruptedError
      |    +-- IsADirectoryError
      |    +-- NotADirectoryError
      |    +-- PermissionError
      |    +-- ProcessLookupError
      |    +-- TimeoutError
      +-- ReferenceError
      +-- RuntimeError
      |    +-- NotImplementedError
      |    +-- RecursionError
      +-- SyntaxError
      |    +-- IndentationError
      |         +-- TabError
      +-- SystemError
      +-- TypeError
      +-- ValueError
      |    +-- UnicodeError
      |         +-- UnicodeDecodeError
      |         +-- UnicodeEncodeError
      |         +-- UnicodeTranslateError
      +-- Warning
           +-- DeprecationWarning
           +-- PendingDeprecationWarning
           +-- RuntimeWarning
           +-- SyntaxWarning
           +-- UserWarning
           +-- FutureWarning
           +-- ImportWarning
           +-- UnicodeWarning
           +-- BytesWarning
           +-- ResourceWarning

chenwx@chenwx:~ $ sudo apt install python-pip
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  python-pip-whl
Recommended packages:
  build-essential python-all-dev python-setuptools python-wheel
The following NEW packages will be installed:
  python-pip python-pip-whl
0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded.
Need to get 1803 kB of archives.
After this operation, 2526 kB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Get:1 http://mirrors.aliyun.com/ubuntu bionic-updates/universe amd64 python-pip-whl all 9.0.1-2.3~ubuntu1 [1652 kB]
Get:2 http://mirrors.aliyun.com/ubuntu bionic-updates/universe amd64 python-pip all 9.0.1-2.3~ubuntu1 [151 kB]
Fetched 1803 kB in 6s (292 kB/s)
Selecting previously unselected package python-pip-whl.
(Reading database ... 294441 files and directories currently installed.)
Preparing to unpack .../python-pip-whl_9.0.1-2.3~ubuntu1_all.deb ...
Unpacking python-pip-whl (9.0.1-2.3~ubuntu1) ...
Selecting previously unselected package python-pip.
Preparing to unpack .../python-pip_9.0.1-2.3~ubuntu1_all.deb ...
Unpacking python-pip (9.0.1-2.3~ubuntu1) ...
Setting up python-pip-whl (9.0.1-2.3~ubuntu1) ...
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
Setting up python-pip (9.0.1-2.3~ubuntu1) ...

chenwx@chenwx:~ $ python -m pip --version
pip 9.0.1 from /usr/lib/python2.7/dist-packages (python 2.7)

chenwx@chenwx:~ $ pip --version
pip 9.0.1 from /usr/lib/python2.7/dist-packages (python 2.7)

chenwx@chenwx:~ $ sudo apt install python3-pip
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  python3-distutils python3-lib2to3
Recommended packages:
  build-essential python3-dev python3-setuptools python3-wheel
The following NEW packages will be installed:
  python3-distutils python3-lib2to3 python3-pip
0 upgraded, 3 newly installed, 0 to remove and 0 not upgraded.
Need to get 331 kB of archives.
After this operation, 2714 kB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Get:1 http://mirrors.aliyun.com/ubuntu bionic-updates/main amd64 python3-lib2to3 all 3.6.7-1~18.04 [76.5 kB]
Get:2 http://mirrors.aliyun.com/ubuntu bionic-updates/main amd64 python3-distutils all 3.6.7-1~18.04 [141 kB]
Get:3 http://mirrors.aliyun.com/ubuntu bionic-updates/universe amd64 python3-pip all 9.0.1-2.3~ubuntu1 [114 kB]
Fetched 331 kB in 3s (113 kB/s)  
Selecting previously unselected package python3-lib2to3.
(Reading database ... 294575 files and directories currently installed.)
Preparing to unpack .../python3-lib2to3_3.6.7-1~18.04_all.deb ...
Unpacking python3-lib2to3 (3.6.7-1~18.04) ...
Selecting previously unselected package python3-distutils.
Preparing to unpack .../python3-distutils_3.6.7-1~18.04_all.deb ...
Unpacking python3-distutils (3.6.7-1~18.04) ...
Selecting previously unselected package python3-pip.
Preparing to unpack .../python3-pip_9.0.1-2.3~ubuntu1_all.deb ...
Unpacking python3-pip (9.0.1-2.3~ubuntu1) ...
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
Setting up python3-lib2to3 (3.6.7-1~18.04) ...
Setting up python3-distutils (3.6.7-1~18.04) ...
Setting up python3-pip (9.0.1-2.3~ubuntu1) ...

chenwx@chenwx:~ $ python3 -m pip --version
pip 9.0.1 from /usr/lib/python3/dist-packages (python 3.6)

chenwx@chenwx:~ $ pip3 --version
pip 9.0.1 from /usr/lib/python3/dist-packages (python 3.6)

chenwx@chenwx:~ $ python3 -m pip
Usage:   
  /usr/bin/python3 -m pip <command> [options]

Commands:
  install                     Install packages.
  download                    Download packages.
  uninstall                   Uninstall packages.
  freeze                      Output installed packages in requirements format.
  list                        List installed packages.
  show                        Show information about installed packages.
  check                       Verify installed packages have compatible dependencies.
  search                      Search PyPI for packages.
  wheel                       Build wheels from your requirements.
  hash                        Compute hashes of package archives.
  completion                  A helper command used for command completion.
  help                        Show help for commands.

General Options:
  -h, --help                  Show help.
  --isolated                  Run pip in an isolated mode, ignoring environment variables and user configuration.
  -v, --verbose               Give more output. Option is additive, and can be used up to 3 times.
  -V, --version               Show version and exit.
  -q, --quiet                 Give less output. Option is additive, and can be used up to 3 times (corresponding to
                              WARNING, ERROR, and CRITICAL logging levels).
  --log <path>                Path to a verbose appending log.
  --proxy <proxy>             Specify a proxy in the form [user:passwd@]proxy.server:port.
  --retries <retries>         Maximum number of retries each connection should attempt (default 5 times).
  --timeout <sec>             Set the socket timeout (default 15 seconds).
  --exists-action <action>    Default action when a path already exists: (s)witch, (i)gnore, (w)ipe, (b)ackup,
                              (a)bort.
  --trusted-host <hostname>   Mark this host as trusted, even though it does not have valid or any HTTPS.
  --cert <path>               Path to alternate CA bundle.
  --client-cert <path>        Path to SSL client certificate, a single file containing the private key and the
                              certificate in PEM format.
  --cache-dir <dir>           Store the cache data in <dir>.
  --no-cache-dir              Disable the cache.
  --disable-pip-version-check
                              Don't periodically check PyPI to determine whether a new version of pip is available for
                              download. Implied with --no-index.

chenwx@chenwx:~ $ python3 -m pip --version
pip 9.0.1 from /usr/lib/python3/dist-packages (python 3.6)

chenwx@chenwx:~ $ python3 -m pip list --format=columns
Package               Version  
--------------------- ---------
apt-clone             0.2.1    
apturl                0.5.2    
attrs                 19.1.0   
backcall              0.1.0    
beautifulsoup4        4.6.0    
bleach                3.1.0    
Brlapi                0.6.6    
certifi               2018.1.18
chardet               3.0.4    
command-not-found     0.3      
configobj             5.0.6    
cupshelpers           1.0      
cycler                0.10.0   
decorator             4.4.0    
defer                 1.0.6    
defusedxml            0.6.0    
entrypoints           0.3      
httplib2              0.9.2    
idna                  2.6      
ipykernel             5.1.1    
ipython               7.5.0    
ipython-genutils      0.2.0    
ipywidgets            7.4.2    
jedi                  0.13.3   
Jinja2                2.10.1   
jsonschema            3.0.1    
jupyter               1.0.0    
jupyter-client        5.2.4    
jupyter-console       6.0.0    
jupyter-core          4.4.0    
kiwisolver            1.1.0    
louis                 3.5.0    
macaroonbakery        1.1.3    
Mako                  1.0.7    
MarkupSafe            1.1.1    
matplotlib            3.0.3    
meld                  3.18.0   
mistune               0.8.4    
mpmath                1.1.0    
nbconvert             5.5.0    
nbformat              4.4.0    
nemo-emblems          4.0.2    
netifaces             0.10.4   
nose                  1.3.7    
notebook              5.7.8    
numpy                 1.16.3   
onboard               1.4.1    
PAM                   0.4.2    
pandas                0.24.2   
pandocfilters         1.4.2    
parso                 0.4.0    
pexpect               4.7.0    
pickleshare           0.7.5    
Pillow                5.1.0    
pip                   9.0.1    
prometheus-client     0.6.0    
prompt-toolkit        2.0.9    
protobuf              3.0.0    
psutil                5.4.2    
ptyprocess            0.6.0    
pycairo               1.16.2   
pycrypto              2.6.1    
pycups                1.9.73   
pycurl                7.43.0.1
Pygments              2.4.0    
pygobject             3.26.1   
PyICU                 1.9.8    
pyinotify             0.9.6    
pymacaroons           0.13.0   
PyNaCl                1.1.2    
pyparsing             2.4.0    
pyRFC3339             1.0      
pyrsistent            0.15.2   
python-apt            1.6.4    
python-dateutil       2.8.0    
python-debian         0.1.32   
python-xapp           1.4.0    
python-xlib           0.20     
pytz                  2019.1   
pyxdg                 0.25     
PyYAML                3.12     
pyzmq                 18.0.1   
qtconsole             4.4.4    
reportlab             3.4.0    
requests              2.18.4   
requests-unixsocket   0.1.5    
scipy                 1.2.1    
Send2Trash            1.5.0    
sessioninstaller      0.0.0    
setproctitle          1.1.10   
setuptools            41.0.1   
six                   1.12.0   
sympy                 1.4      
system-service        0.3      
systemd-python        234      
terminado             0.8.2    
testpath              0.4.2    
tornado               6.0.2    
traitlets             4.3.2    
ubuntu-drivers-common 0.0.0    
ufw                   0.36     
urllib3               1.22     
wcwidth               0.1.7    
webencodings          0.5.1    
widgetsnbextension    3.4.2    
xkit                  0.0.0    

chenwx@chenwx:~ $ python3 -m pip search numpy
numpy (1.16.3)                         - NumPy is the fundamental package for array computing with Python.
  INSTALLED: 1.16.3 (latest)
numpy-utils (0.1.3)                    - NumPy utilities.
numpy-cloud (0.0.5)                    - Numpy in the cloud
numpy-turtle (0.1)                     - Turtle graphics with NumPy
numpy-sugar (1.5.0)                    - Missing NumPy functionalities
root-numpy (4.8.0)                     - The interface between ROOT and NumPy
msgpack-numpy (0.4.4.3)                - Numpy data serialization using msgpack
numpy-quaternion (2019.3.21.14.22.55)  - Add built-in support for quaternions to numpy
numpy-partition (1.18.9)               - SQL PARTITION BY and window functions for NumPy
mapchete-numpy (0.1)                   - Mapchete NumPy read/write extension
numpy-posit (1.15.2.0.0.1.dev2)        - posit (unum type III) integrated NumPy.
intel-numpy (1.15.1)                   - NumPy optimized with Intel(R) MKL library
numpy-mkl (1.10.2)                     - NumPy: array processing for numbers, strings, records, and objects.
ccv-numpy (0.0.2)                      - Wrapper module for ccv using numpy arrays interface
django-numpy (1.0.1)                   - Application for Django projects that adds some utilities and integration tools with Numpy.
BSON-NumPy (0.1)                       - Module for converting directly from BSON to NumPy ndarrays and vice versa
dicom-numpy (0.1.6)                    - Extract image data into a 3D numpy array from a set of DICOM files.
dl-with-numpy (0.0.3)                  - Simple deep learning with numpy
numpy-html (0.0.3)                     - A simple table renderer for numpy arrays. Provides a rich display hook for use with Jupyter Lab / Notebook.
numpy-indexed (0.3.5)                  - This package contains functionality for indexed operations on numpy ndarrays, providing efficient vectorized functionality such as grouping and set operations.
numpy-image-widget (2019.1.6)          - An easy-to-use Jupyter widget for displaying images from Numpy data arrays
django-numpy-json-encoder (0.1.3)      - Django JSON encoder with numpy support.
faster-numpy (0.1.2)                   -
numpy-stl (2.10.1)                     - Library to make reading, writing and modifying both binary and ascii STL files easy.
hypothesis-numpy (2.0.0)               - Adds support for generating datetime to Hypothesis
numpy-groupies (0.9.9)                 - Optimised tools for group-indexing operations: aggregated sum and more.
npplus (0.9.8)                         - Enhancements to Numpy
o243kgmvs924mtvd034mg (0.01)           - NumPy Testing
np (1.0.2)                             - np = numpy++: numpy with added convenience functionality
maskedarray (0.1)                      - NumPy Masked Array
jumpy (0.2.4)                          - Numpy and nd4j interop
nparray (1.0.0)                        - Numpy Array Helpers
oldnumeric (1.0.4)                     - The oldnumeric numpy package
nptyping (0.2.0)                       - Type hints for Numpy
match-arrays (0.0.1)                   - Matching of Numpy arrays
vidsrc (2019.1.1)                      - Video Frameserver for Numpy
ndarray (0.8)                          - Tools for numpy ndarray
wrapnumpy3 (0.0.3)                     - Wrapper of Numpy in Python3.
sqlite3ndarray (0.3.1)                 - sqlite3 helpers for numpy ndarrays
axarray (0.1.1)                        - numpy array with labeled axes
somber (2.0.1)                         - Self-Organizing Maps in Numpy
gsn_numpy_util (0.1.0)                 - Toolbox for working with Numpy arrays.
homog (0.1.14)                         - Utilities for Homogeneous Coordinates with Numpy
npstreams (1.6)                        - Streaming operations on NumPy arrays
sym2num (0.1.dev2)                     - Sympy to numpy code generator.
blocked-matrix-utils (1.0.1)           - NumPy wrappers for blocked matrices
dynarray (0.1.3)                       - Dynamically growable numpy arrays.
zappy (0.2.0)                          - Distributed processing with NumPy and Zarr.
permanent (1.1.1)                      - Calculates the permanent of a Numpy matrix
pstar (0.1.6)                          - pstar: numpy for arbitrary data
sompy (0.1.1)                          - Numpy based SOM Library
spartan (0.06)                         - Distributed Numpy-like arrays.
fastjet (0.0.3)                        - The interface between FastJet and NumPy
npdoc (1.0.1)                          - In-notebook NumPy man pages
gumpy (0.0.1)                          - GPU-accelerated NumPy API
wendelin.core (0.12)                   - Out-of-core NumPy arrays
sampyl-mcmc (0.3)                      - MCMC Samplers in Python & Numpy
gnuplotlib (0.29)                      - Gnuplot-based plotting for numpy
multipolyfit (0.0.1)                   - Multivariate Polynomial fitting with NumPy
nppretty (1.0.0)                       - Pretty printer for numpy arrays.
numpythia (1.1.0)                      - The interface between PYTHIA and NumPy
PyUblas (2017.1)                       - Seamless Numpy-UBlas interoperability
numm (0.3)                             - numpy-based multimedia library
ntype (0.0.1)                          - Type Handler using NumPy
fastfunc (0.1.7)                       - Fast numpy ufunc operations
pyjet (1.5.0)                          - The interface between FastJet and NumPy
snuggs (1.4.6)                         - Snuggs are s-expressions for Numpy
array_collections (0.1.7)              - A collection of numpy ndarray subclasses.
pyache (0.1.0)                         - A simple numpy caching library
opt-einsum (2.3.2)                     - Optimizing numpys einsum function
arkouda (0.0.0)                        - A numpy replacement backed by Chapel
fastremap (1.5.2)                      - Remap and renumber numpy arrays.
fewerbytes (0.0.1)                     - Compression techniques for numpy arrays
numpy_ringbuffer (0.2.1)               - Ring buffer implementation for numpy
bohrium (0.11.0.post15)                - Bohrium Python/NumPy Backend
afnumpy (1.3)                          - A GPU-ready drop-in replacement for numpy
ComStats (0.1.0)                       - Do combinatorial statistics on numpy ndarrays
xcy-Zscore (0.0.5)                     - A small tool of Zscore based on numpy
marshmallow-numerical (0.0.2)          - Marshmallow Schema generator for pandas and numpy
numpyx (0.3.0)                         - Utility functions for numpy, written in cython
sortednp (0.2.1)                       - Merge and intersect sorted numpy arrays.
numphy (0.0.2)                         - Physics objects backed by NumPy and/or TensorFlow.
vector-shortcuts (0.2.0)               - Vector and linear algebra toolbelt for NumPy
zmqnumpy (0.1)                         - numpy array over zmq sockets
pynetcdf (0.7)                         - Standalone Scientific.IO.NetCDF (2.4.11) built for NumPy
npcb (0.0.1)                           - Copy NumPy arrays via the clipboard
spacegrids (1.9)                       - numpy array with grids and associated operations
ndf (0.1.4)                            - NumPy based deep learning framework
multipletau (0.3.3)                    - A multiple-tau algorithm for Python/NumPy
seabred (0.0.1)                        - Seaborn-like plots for numpy arrays
numexpr (2.6.9)                        - Fast numerical expression evaluator for NumPy
tensorfont (0.0.2)                     - Turn font glyphs into numpy arrays
numpy_display (1.2.0)                  - Formats numpy matrices in an IPython Notebook
nnlib (0.2)                            - numpy only neural network library
matplottery (1.0.4)                    - Nicer histograms with numpy and plotting with matplotlib
geog (0.0.2)                           - Numpy-based vectorized geospatial functions
stft (0.5.2)                           - Short Time Fourier transform for NumPy.
hdrpy (0.3.3)                          - HDR histogram implementation based on numpy
np2d (0.1.1)                           - Common 2-D NumPy operations.
pySLALIB (1.0.4)                       - f2py and numpy based wrappers for SLALIB

chenwx@chenwx:~ $ python3 -m pip install numpy
Collecting numpy
  Downloading https://files.pythonhosted.org/packages/e0/b5/63b79fe426433fa1cd110eb04a94ec0c6967e56e5f57c98caf455a5fb6e2/numpy-1.16.1-cp27-cp27mu-manylinux1_x86_64.whl (17.0MB)
    100% |################################| 17.0MB 51kB/s
Installing collected packages: numpy
Successfully installed numpy-1.16.1

chenwx@chenwx:~ $ python3 -m pip show numpy
Name: numpy
Version: 1.16.1
Summary: NumPy is the fundamental package for array computing with Python.
Home-page: https://www.numpy.org
Author: Travis E. Oliphant et al.
Author-email: None
License: BSD
Location: /home/chenwx/.local/lib/python2.7/site-packages
Requires:

chenwx@chenwx:~ $ python3
Python 3.6.7 (default, Oct 22 2018, 11:32:17)
[GCC 8.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy  
>>> numpy.eye(4)
array([[1., 0., 0., 0.],
       [0., 1., 0., 0.],
       [0., 0., 1., 0.],
       [0., 0., 0., 1.]])

$ pip install --upgrade autopep8

$ autopep8 --in-place --aggressive <filename>

>>> import site
>>> site.getusersitepackages()
'/home/ewaadex/.local/lib/python3.5/site-packages'