what is s._Spam__egg do ??

Question

class Spam:
__egg = 7
def print_egg(self):
print(self.__egg)

s = Spam()
s.print_egg()
print(s._Spam__egg)
print(s.__egg)

what is s._Spam__egg do ??

how it works

Answer 1

__egg is a variable that is created when you create a new instance of the class Spam, in this case 's'. If a variable has two underscores before it (__) then it is considered highly private and cannot be called by the standard method of for example s.egg.

So even though __egg is highly private, you can still (although not recommended) access that variable outside the class if you really need to. To do that you do a special method call with the instance of the class, the class name preceded by an underscore and then the private variable name. That is how you get

s._Spam__egg

which works when you try and print it out in the above statement, but printing s.__egg throws an error.