Python match/case internals "hacky" class which allows one to match ranges without needing any expression guards

range_matcher.py

class Comparator:
    def __init__(self, value, stage):
        self.value = value
        self.stage = stage
    def __eq__(self, other):
        return self.value >= other if self.stage == "start" else self.value < other

class Interval:
    __match_args__ = ("start", "stop")
    def __init__(self, value):
        self.value = value
    @property
    def start(self):
        return Comparator(self.value, "start")
    @property
    def stop(self):
        return Comparator(self.value, "stop")
    def __repr__(self):
        return f"Wrapped value for range matching: {self.value}"

def m(n):
    match Interval(n):
        case Interval(0, 2):
            print("first")
        case Interval(2, 5):
            print("second")
        case Interval():
            print("any")
        case _:
            print("not found")

The difficulty about matching ranges is that in a match/case statement, the literal values that would specify any range in a line like case Interval(0, 2): are never forwarded to the interval class: rather, they are kept in the code object where the match/case body is run. However, the __match_args__ mechanism allows that the values that are tested for equality with` those limits to be fetched from the Interval instance that is being compared.

So, the drawback is that the value to be range-checked have itself to be wrapped in an "Interval" class. Other than that, the ~20LoC above are enough to make everything work.