Python 201 - Interactively Learn Advanced Concepts in Python 3/

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Functools: functools.singledispatch

Functools: functools.singledispatch

Let's discover functool modules and how functions can be overloaded.

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Overview of singledispatch module

Python recently added partial support for function overloading in Python 3.4. They did this by adding a neat little decorator to the functools module called singledispatch. This decorator will transform our regular function into a single dispatch generic function. Note however that singledispatch only happens based on the first argument’s type.

Simple example of singledispatch()

Let’s take a look at an example to see how this works!

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from functools import singledispatch
@singledispatch
def add(a, b):
    raise NotImplementedError('Unsupported type')
@add.register(int)
def _(a, b):
    print("First argument is of type ", type(a))
    print(a + b)
@add.register(str)
def _(a, b):
    print("First argument is of type ", type(a))
    print(a + b)
@add.register(list)
def _(a, b):
    print("First argument is of type ", type(a))
    print(a + b)
if __name__ == '__main__':
    add(1, 2)
    add('Python', 'Programming')
    add([1, 2, 3], [5, 6, 7])

Here we import ...