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pythonpep8

Is using magic methods in high level Python code is allowed by PEP8?

Is using magic methods in high level Python code is allowed by PEP8 ? For example, does PEP8 allows for:

ab = {'a', 'b'}
ab.__len__()

?

I often write code in editors when it's much easier to write left to right without going back to the beginning of a line.

Solution

  • Calling __len__ directly doesn't violate PEP8, however, should be avoided as the inbuilt functions that use the magic methods do additional checks.

    Example:

    class Test:

    def __len__(self):
        return "hi"


print(Test().__len__()) # Prints hi
print(len(Test()))  # Prints "TypeError: 'str' object cannot be interpreted as an integer"