Why does Python use 'magic methods'?

Question

I\'ve been playing around with Python recently, and one thing I\'m finding a bit odd is the extensive use of \'magic methods\', e.g. to make its length available, an object

Answer 1

Python uses the word "magic methods", because those methods really performs magic for you program. One of the biggest advantages of using Python's magic methods is that they provide a simple way to make objects behave like built-in types. That means you can avoid ugly, counter-intuitive, and nonstandard ways of performing basic operators.

Consider a following example:

dict1 = {1 : "ABC"}
dict2 = {2 : "EFG"}

dict1 + dict2
Traceback (most recent call last):
  File "python", line 1, in 
TypeError: unsupported operand type(s) for +: 'dict' and 'dict'

This gives an error, because the dictionary type doesn't support addition. Now, let's extend dictionary class and add "__add__" magic method:

class AddableDict(dict):

    def __add__(self, otherObj):
        self.update(otherObj)
        return AddableDict(self)


dict1 = AddableDict({1 : "ABC"})
dict2 = AddableDict({2 : "EFG"})

print (dict1 + dict2)

Now, it gives following output.

{1: 'ABC', 2: 'EFG'}

Thus, by adding this method, suddenly magic has happened and the error you were getting earlier, has gone away.

I hope, it makes things clear to you. For more information, refer to:

A Guide to Python's Magic Methods (Rafe Kettler, 2012)