How Can I Replace Switch Statements in Python?

Alternatives to Switch Statements in Python

When coding functions in Python that return different fixed values based on an input index, finding a suitable replacement for switch or case statements, which are commonly utilized in other languages, can be beneficial.

Python's Switch Statement Alternative: Match-Case Statement

Python 3.10 introduced the match-case statement, which serves as an effective substitute for switch statements. It offers a comprehensive implementation with significant flexibility beyond the simple example below:

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

Comprehensive documentation and resources can be found at:

• [Switch Statements (Under Structural Pattern Matching)](https://docs.python.org/3/library/dataclasses.html#match-statements)
• [Match Statement (Under Compound Statements)](https://docs.python.org/3/reference/compound_stmts.html#the-match-statement)
• [PEP 634 - Structural Pattern Matching: Specification](https://peps.python.org/pep-0634/)
• [PEP 636 - Structural Pattern Matching: Tutorial](https://peps.python.org/pep-0636/)

Dictionary Alternative for Python ≤ 3.9

If compatibility with Python versions ≤ 3.9 is necessary, utilizing a dictionary can offer a versatile alternative:

def f(x):
    return {
        'a': 1,
        'b': 2,
    }.get(x, 0)  # Default case: 0 is returned if 'x' is not found

This method allows for efficient key-based value lookup from a dictionary, providing a straightforward solution for your requirement.

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