Question

Lately, I was looking at some Python idioms.
I found many descriptions of protocols used in Python, such as the ordering (__cmp__, …) or generators. Besides, there are also methods like __hash__ which are defined for every object (I suppose).

After some search on the internet, I haven’t found a comprehensive list of these protocols and methods.
Can anyone give me some pointers URLs?

Answer 1

Your best reference is always going to be the Python Online Documentation, specifically the section on Special method names.

The interactive Python interpretor is a very useful tool, too. Try some of these:

>>> dir(object)
['__class__', '__delattr__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__le__', '__lt__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__']
>>> help(object.__class__)

>>> help(object.__hash__)

>>> help(hash)