Python — Match

switch's cooler Python cousin

match compares a value against patterns and runs the first matching block (Python 3.10+):

command = "start"

match command:
    case "start":
        print("Starting…")
    case "stop":
        print("Stopping")
    case _:
        print("Unknown command")     # _ = default/catch-all

Capture patterns — match into a variable

A bare name matches ANYTHING and binds it:

match point:
    case (0, 0):
        print("origin")
    case (x, y):                     # captures both parts
        print(f"at {x}, {y}")

That example also shows sequence unpacking — match works on lists/tuples by shape, not just equality.

Or-patterns

Several alternatives, one body:

match key:
    case "q" | "quit":
        running = False
    case "h" | "help":
        show_help()

Guards — extra conditions with if

match score:
    case n if n >= 90:
        grade = "A"
    case n if n >= 80:
        grade = "B"
    case _:
        grade = "F"

The guard decides; the capture names the value.

Destructuring objects

Match can reach inside dicts and class instances:

match user:
    case {"role": "admin", "name": name}:
        print(f"Admin {name}")
    case {"role": role, "name": name}:
        print(f"{role}: {name}")

Class patterns check type + fields:

match event:
    case Click(x=x, y=y):
        print(f"click at {x},{y}")
    case KeyPress(key="Enter"):
        submit()

match vs if/elif

Use match when	Use if/elif when
One value against many shapes/literals	conditions involve different variables
Destructuring structures	simple range checks
Command parsers, state machines	quick two-way branches

Ranges need guards (if n >= 90), so plain number grading is often clearer as if/elif — match shines on structure.

Gotchas: requires Python ≥ 3.10 · bare case x: before later cases swallows everything (it's a catch-all!) · _ matches without binding.

Mini Practice

1. Command parser: start/stop/help/quit via or-patterns.
2. Tuple matcher distinguishing 2D origin, axes, general points.
3. Dict pattern routing API payloads by "type".
4. Guard-based HTTP status handler (2xx/4xx/5xx).
5. Rewrite an if/elif tower as match — judge readability honestly.

Next: while loops →