python: What happens when class attribute, instance attribute, and method all have the same name?

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Class attributes are accessible through the class:

YourClass.clsattribute

or through the instance (if the instance has not overwritten the class attribute):

instance.clsattribute

Methods, as stated by ecatmur in his answer, are descriptors and are set as class attributes.

If you access a method through the instance, then the instance is passed as the self parameter to the descriptor.
If you want to call a method from the class, then you must explicitly pass an instance as the first argument. So these are equivalent:

instance.method()
MyClass.method(instance)

Using the same name for an instance attribute and a method will make the method hidden via the instance, but the method is still available via the class:

#python3
>>> class C:
...     def __init__(self):
...         self.a = 1
...     def a(self):
...         print('hello')
... 
>>> C.a
<function a at 0x7f2c46ce3c88>
>>> instance = C()
>>> instance.a
1
>>> C.a(instance)
hello

Conclusion: do not give the same name to instance attributes and methods.
I avoid this by giving meaningful names. Methods are actions, so I usually use verbs or sentences for them. Attributes are data, so I use nouns/adjectives for them, and this avoids using the same names for both methods and attributes.

Note that you simply cannot have a class attribute with the same name as a method, because the method would completely override it (in the end, methods are just class attributes that are callable and that automatically receive an instance of the class as first attribute).

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