Python leading underscore _variables

Question

We know that in a class, functions starting with __function__ do not get imported while using:

from module import *

Someone as

Answer 1

A variable name starting with an underscore is a strong hint that this variable should be viewed as private.

Read http://docs.python.org/tutorial/classes.html#private-variables

Answer 2

It is a naming convention for private variables. See 9.6, private variables: http://docs.python.org/tutorial/classes.html#private-variables