Python Class scope & lists

Question

I\'m still fairly new to Python, and my OO experience comes from Java. So I have some code I\'ve written in Python that\'s acting very unusual to me, given the following code:<

Answer 1

I believe the difference is that += is an assignment (just the same as = and +), while append changes an object in-place.

    mylist = []
    mynum = 0

This assigns some class variables, once, at class definition time.

    self.mylist.append("Hey!")

This changes the value MyClass.mylist by appending a string.

    self.mynum += 1

This is the same as self.mynum = self.mynum + 1, i.e., it assigns self.mynum (instance member). Reading from self.mynum falls through to the class member since at that time there is no instance member by that name.