Underscores and Dunders

• __name__: dunder methods
  • We use dunder methods when we’re overriding something that exists in python, something that python looks for
  • __init__
  • Reserved for special methods that have predefined behaviors and are part of python’s core functionality
  • just don’t use it
• _name: 1 underscore
  • indicates a private property
  • self._secret
  • OFC, nothing is really “private” in Python, so it’s just a convention
• __name : 2 underscores
  • self.__message
  • This is name mangling!
    • changing the names of class attributes that start with a double underscore __
    • change the attribute name to something that is less likely to conflict with subclasses
    • It makes the attribute unique to the specific class

class Person:
	def __init__(self):
		self.name = "Tony"
		self._secret = "hi"
		self.__msg = "I like turtles!"
p = Person()
 
print(p.name)
print(p.__msg) ## DOESN'T PRINT
print(dir(p))
# here, you sill see '_Person__msg' along with other methods
# so you have to do like this
print(p._Person_msg) # this prints "I like turtles!"

• single underscore, class name, double underscore, and the attribute