switchcase

A "better" switch statement for Python

WARNING: this isn't a serious attempt at adding switch/case to Python because it's a terrible idea, I just wanted to come up with a better syntax than https://github.com/mikeckennedy/python-switch

Usage

Traditional Switch/Case

This version uses metaclasses and variable annotations to define switches. It supports all the usual stuff including fallthrough via return False

from switchcase import Switch

class _(Switch):
    switch: 1 + 1
    def case(when: 1):
        print("Not a match")
    def case(when: 2):
        print("First match!")
    def case(when: 3):
        print("Oh no, I fell through")
        return False
    def case(when: 4):
        print("Oops! Too far!")
    def default():
        print("Not triggered")

# Prints:
# First match!
# Oh no, I fell through
# Note that the switch is run when the class is defined, you do not need to instantiate it.

Context manager form without fallthrough

from switchcase import select

with select as (switch, case):
    try: switch(2)
    except case(1):
        print("wrong")
    except case(2):
        print("right")
# Prints:
# right

Global form without implicit default or fallthrough

from switchcase import switch, case

try: switch(2)
except case(1):
    print("wrong")
except case(2):
    print("right")
else:
    pass