pythonswitch-statement

Replacements for switch statement in Python?


I want to write a function in Python that returns different fixed values based on the value of an input index.

In other languages I would use a switch or case statement, but Python does not appear to have a switch statement. What are the recommended Python solutions in this scenario?


Solution

  • Python 3.10 (2021) introduced the match-case statement, which provides a first-class implementation of a "switch" for Python. For example:

    def f(x):
        match x:
            case 'a':
                return 1
            case 'b':
                return 2
            case _:
                return 0   # 0 is the default case if x is not found
    

    The match-case statement is considerably more powerful than this simple example.

    Documentation:


    If you need to support Python ≤ 3.9, use a dictionary instead:

    def f(x):
        return {
            'a': 1,
            'b': 2,
        }.get(x, 0)  # default case