Underscore Python

double_leading_python.py

class Sample():

    def __init__(self):
        self.a = 1
        self._b = 2
        self.__c = 3


>>> t = Sample()
>>> dir(t)
['_Sample__c', '__class__', '__delattr__', 
'__dict__', '__dir__', '__doc__', '__eq__', 
'__format__', '__ge__', '__getattribute__', 
'__gt__', '__hash__', '__init__', '__init_subclass__', 
'__le__', '__lt__', '__module__', '__ne__', 
'__new__', '__reduce__', '__reduce_ex__', 
'__repr__', '__setattr__', '__sizeof__', '__str__', 
'__subclasshook__', '__weakref__', '_b', 'a']