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Andrew Ge
2,158 PointsDict Methods: Nomenclature
When Kenneth accessed the list of methods that a dict could use, a lot of the methods had two "_ _" around it. What does that mean?
1 Answer
Chris Freeman
Treehouse Moderator 68,441 PointsAccording to PEP-8: __double_leading_and_trailing_underscore__ are "magic" objects or attributes that live in user-controlled namespaces. E.g. __init__ , __import__ or __file__. Never invent such names; only use them as documented.
When you run the command dir() on an object to list the object attributes , behind the scenes Python is actually calling the object.__dir__() method. Many actions in Python get redirected to "dunder" methods. Another example is len(object) actually calls the object.__len__() method. While PEP-8 advises not to create your own dunder methods, you can (and often will) overwrite the dunder methods of a parent class (This will get covered later when the Python track covers classes)..