python模块内置属性概念及实例

print(__doc__)
print(__file__)
print(__name__)

# test.py
# -*- coding: utf-8 -*-
"""
some doc
"""
import os
var1 = None
class Person(object):
  pass

if __name__ == "__main__":
  print(dir()) # ['Person', '__annotations__', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', 'os', 'var1']

print(__name__) # __main__
print(__annotations__) # {}
print(__builtins__) # <module 'builtins' (built-in)>
print(__cached__) # None
print(__doc__) # some doc
print(__file__) # .../test.py
print(__loader__) # <_frozen_importlib_external.SourceFileLoader object at 0x000002398E831F28>
print(__package__) # None
print(__spec__) # None

# 其中__name__、__doc__、__file__、__package__是可以直接使用的，其它的内置属性一般不允许直接使用。