Finding a list of all double-underscore variables?

Question

Related: What is the common header format of Python files?

Where can I find a list of all double-underscore variables/keywords that are commonly used in Pyth

Answer 1

The complete list used by Python is given in the Python Language Reference section 3, "Data model". Every other one is non-standard or used by third-party modules and is documented separately.

Answer 2

If you want to see magic names whether documented or not, go to the Lib directory and run:

egrep -oh '__[A-Za-z_][A-Za-z_0-9]*__' *.py | sort | uniq

That produces:

'__all__'
'__args__'
'__author__'
'__bases__'
'__builtin__'
'__builtins__'
'__cached__'
'__call__'
'__class__'
'__copy__'
'__credits__'
'__date__'
'__decimal_context__'
'__deepcopy__'
'__dict__'
'__doc__'
'__exception__'
'__file__'
'__flags__'
'__ge__'
'__getinitargs__'
'__getstate__'
'__gt__'
'__import__'
'__importer__'
'__init__'
'__ispkg__'
'__iter__'
'__le__'
'__len__'
'__loader__'
'__lt__'
'__main__'
'__module__'
'__mro__'
'__name__'
'__package__'
'__path__'
'__pkgdir__'
'__return__'
'__safe_for_unpickling__'
'__setstate__'
'__slots__'
'__temp__'
'__test__'
'__version__'

Answer 3

There is a comprehensive list of the dunders and their usage that I like here: magicmethods

Answer 4

when i use

dir(object)

i got these:

'__class__', '__delattr__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__has
h__', '__init__', '__init_subclass__', '__le__', '__lt__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__'
, '__setattr__', '__sizeof__', '__str__', '__subclasshook__'

and i think they are the dunder names every object will have in python