Why accessing to class variable from within the class needs “self.” in Python? [duplicate]

Answer 1

It seems to be related to module vs. class scope handling, in Python:

COLOR = 'blue'

class TellColor(object):
    COLOR = 'red'

    def tell(self):
        print self.COLOR   # references class variable
        print COLOR        # references module variable

a = TellColor()
a.tell()

> red
> blue