I'm not sure that it's a good reason, but the explicit self allows for weird intermingling of functions and members. For instance, class foo: def

I'm not sure that it's a good reason, but the explicit self allows for weird intermingling of functions and members. For instance, class foo: def __init__(self,val): self.x=val def square(self): return self.x**2 #imperative way imperative = [foo(x).square() for x in range(5)] #functional way s = foo.square composed = lambda x: s(foo(x)) functional = map(composed,range(5)) print imperative==functional The explicit self allows you to treat member functions as generic function and compose them in a functional way. Now, most functional programming isn't necessarily Pythonic. However, given a proper compose function, I could imagine it being useful to mix a long chain of function and member calls without needing to make a distinction between the two.