No, they aren't exactly the same:

    x = 0
    def foo():
        x = x + 1
        print x

    UnboundLocalError: local variable 'x' referenced before assignment

The javascript version works fine.

    var x = 0;
    var foo = function() { x = x + 1; console.log(x); }

I realize there are ways around this, but they are considered unpythonic. For example:

    x = [0]
    def foo():
        x[0] = x[0] + 1
        print x[0]

This works as you'd expect.