6. (Module)

Python (script)

Python (module) import import (main)

Python .py __name__ fibo.py 

# 

def fib(n):
    """ n """
    a, b = 0, 1
    while a < n:
        print(a, end=' ')
        a, b = b, a+b
    print()

def fib2(n):
    """ n """
    result = []
    a, b = 0, 1
    while a < n:
        result.append(a)
        a, b = b, a+b
    return result

Python import 

>>> import fibo

fibo namespace Python (Scope) (Namespace) fibo 

>>> fibo.fib(1000)
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987
>>> fibo.fib2(100)
[0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]
>>> fibo.__name__
'fibo'


>>> fib = fibo.fib
>>> fib(500)
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

6.1.

import [1]

(namespace)modname.itemname

import import class import

import import import 

>>> from fibo import fib, fib2
>>> fib(500)
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

import fibo

import 

>>> from fibo import *
>>> fib(500)
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

import (_) Python

import *

as as import 

>>> import fibo as fib
>>> fib.fib(500)
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

import import fibo fib

from 

>>> from fibo import fib as fibonacci
>>> fibonacci(500)
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

session import importlib.reload()import importlib; importlib.reload(modulename)

6.1.1.

Python 

python fibo.py <arguments>

import __name__ "__main__"

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

import (parse) 

$ python fibo.py 50
0 1 1 2 3 5 8 13 21 34

import 

>>> import fibo
>>>

6.1.2.

Import spam sys.builtin_module_names sys.path spam.py sys.path

sys.path

(symlink)

Python sys.path

6.1.3. Python

Python __pycache__ module.version.pyc version Python CPython 3.3 spam.py __pycache__/spam.cpython-33.pyc Python

Python

Python (cache)

6.2.

Python Python winreg Windows sys Python sys.ps1 sys.ps2 

>>> import sys
>>> sys.ps1
'>>> '
>>> sys.ps2
'... '
>>> sys.ps1 = 'C> '
C> print('Yuck!')
Yuck!
C>

sys.path list PYTHONPATH PYTHONPATH list 

>>> import sys
>>> sys.path.append('/ufs/guido/lib/python')

6.3. dir()

dir() list

>>> import fibo, sys
>>> dir(fibo)
['__name__', 'fib', 'fib2']
>>> dir(sys)
['__breakpointhook__', '__displayhook__', '__doc__', '__excepthook__',
 '__interactivehook__', '__loader__', '__name__', '__package__', '__spec__',
 '__stderr__', '__stdin__', '__stdout__', '__unraisablehook__',
 '_clear_type_cache', '_current_frames', '_debugmallocstats', '_framework',
 '_getframe', '_git', '_home', '_xoptions', 'abiflags', 'addaudithook',
 'api_version', 'argv', 'audit', 'base_exec_prefix', 'base_prefix',
 'breakpointhook', 'builtin_module_names', 'byteorder', 'call_tracing',
 'callstats', 'copyright', 'displayhook', 'dont_write_bytecode', 'exc_info',
 'excepthook', 'exec_prefix', 'executable', 'exit', 'flags', 'float_info',
 'float_repr_style', 'get_asyncgen_hooks', 'get_coroutine_origin_tracking_depth',
 'getallocatedblocks', 'getdefaultencoding', 'getdlopenflags',
 'getfilesystemencodeerrors', 'getfilesystemencoding', 'getprofile',
 'getrecursionlimit', 'getrefcount', 'getsizeof', 'getswitchinterval',
 'gettrace', 'hash_info', 'hexversion', 'implementation', 'int_info',
 'intern', 'is_finalizing', 'last_traceback', 'last_type', 'last_value',
 'maxsize', 'maxunicode', 'meta_path', 'modules', 'path', 'path_hooks',
 'path_importer_cache', 'platform', 'prefix', 'ps1', 'ps2', 'pycache_prefix',
 'set_asyncgen_hooks', 'set_coroutine_origin_tracking_depth', 'setdlopenflags',
 'setprofile', 'setrecursionlimit', 'setswitchinterval', 'settrace', 'stderr',
 'stdin', 'stdout', 'thread_info', 'unraisablehook', 'version', 'version_info',
 'warnoptions']

dir() 

>>> a = [1, 2, 3, 4, 5]
>>> import fibo
>>> fib = fibo.fib
>>> dir()
['__builtins__', '__name__', 'a', 'fib', 'fibo', 'sys']

dir() builtins 

>>> 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',
 'ReferenceError', 'ResourceWarning', 'RuntimeError', 'RuntimeWarning',
 'StopIteration', 'SyntaxError', 'SyntaxWarning', 'SystemError',
 'SystemExit', 'TabError', 'TimeoutError', 'True', 'TypeError',
 'UnboundLocalError', 'UnicodeDecodeError', 'UnicodeEncodeError',
 'UnicodeError', 'UnicodeTranslateError', 'UnicodeWarning', 'UserWarning',
 'ValueError', 'Warning', 'ZeroDivisionError', '_', '__build_class__',
 '__debug__', '__doc__', '__import__', '__name__', '__package__', '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']

6.4. (Package)

Python A.B A B NumPy Pillow

.wav.aiff.au

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 Python sys.path

__init__.py Pyhon namespace package string__init__.py __all__

import 

import sound.effects.echo

sound.effects.echo

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

import 

from sound.effects import echo

echo

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

import 

from sound.effects.echo import echofilter

echo echofilter() 

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

from package import item item class import item item ImportError

import item.subitem.subsubitem class

6.4.1. import *

from sound.effects import * import import import

import __init__.py __all__ list from package import * import list import * listsound/effects/__init__.py 

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

from sound.effects import * import sound.effects

(locally defined) sound/effects/__init__.py reverse from sound.effects import * echo surround reverse reverse 

__all__ = [
    "echo",      #  'echo.py' 
    "surround",  #  'surround.py' 
    "reverse",   # !!!  'reverse'  !!!
]

def reverse(msg: str):  #  <--  'from sound.effects import *' 
    return msg[::-1]    #      'reverse.py'

__all__ from sound.effects import * sound.effects import sound.effects import __init__.py import __init__.py import 

import sound.effects.echo
import sound.effects.surround
from sound.effects import *

from...import echo surround import sound.effects __all__

import * (production)

from package import specific_submodule import

6.4.2.

sound (absolute) import sound.filters.vocoder sound.effects echo from sound.effects import echo

from module import name import (relative) import import import surround 

from . import echo
from .. import formats
from ..filters import equalizer

import Python

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