I’ve opened an issue and a pull request that adds a test case for this and fixes the bug. Django has 327,000 lines of code, including tests. Of these, there are 905 uses of elif, or 0.3%. Example from Django admin checks, in _check_fieldsets_item(). The structural matching is great here, but doesn’t help produce good error messages. def _check_fieldsets_item(self, obj, fieldset, label, seen_fields): if not isinstance(fieldset, (list, tuple)): return must_be('a list or tuple', option=label, obj=obj, id='admin.E008') elif len(fieldset) != 2: return must_be('of length 2', option=label, obj=obj, id='admin.E009') elif not isinstance(fieldset[1], dict): return must_be('a dictionary', option='%s[1]' % label, obj=obj, id='admin.E010') elif 'fields' not in fieldset[1]: return [ checks.Error( "The value of '%s[1]' must contain the key 'fields'."

def http_error(status): match status: case 400: return "Bad request" case 404: return "Not found" case 418: return "I'm a teapot" case _: return "Something's wrong with the Internet" Note the last block: the “variable name” _ acts as a wildcard and never fails to match. You can combine several literals in a single pattern using | (“or”): ... # point is an (x, y) tuple match point: case (0, 0): print("Origin") case (0, y): print(f"Y={y}") case (x, 0): print(f"X={x}") case (x, y): print(f"X={x}, Y={y}") case _: raise ValueError("Not a point")

December 11, 2025 - The match-case statement is particularly powerful when working with sequences such as lists or tuples.

Like unpacking assignment, both tuple-like and list-like syntax can be used, with identical semantics. Each element can be an arbitrary pattern; there may also be at most one *name pattern to catch all remaining items: match collection: case 1, [x, *others]: print("Got 1 and a nested sequence") case (1, x): print(f"Got 1 and {x}")

plot1 = (0, 4) match plot1: case (4,0): print('on x-axis') case (0,4): print('on y-axis') case (0,0): print('center') # Output: on y-axis · In the above example, we have created a tuple named plot1 with values: 0 and 4.

Python match-case statements can be used to check the types of something being passed in. In the code below, lists [ ], tuples ( ) and sets { } are distinguished.

June 1, 2024 - Matches a value against a single pattern. match x: case 1: print(“x is 1”) case 2: print(“x is 2”) ... A simple match case statement that matches the value of x against the patterns 1 and 2. Matches a tuple against multiple patterns.

month = 5 day = 4 match day: case 1 | 2 | 3 | 4 | 5 if month == 4: print("A weekday in April") case 1 | 2 | 3 | 4 | 5 if month == 5: print("A weekday in May") case _: print("No match") Try it Yourself » ... If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail: sales@w3schools.com · If you want to report an error, or if you want to make a suggestion, send us an e-mail: help@w3schools.com · HTML Tutorial CSS Tutorial JavaScript Tutorial How To Tutorial SQL Tutorial Python Tutorial W3.CSS Tutorial Bootstrap Tutorial PHP Tutorial Java Tutorial C++ Tutorial jQuery Tutorial

def http_error(status): match status: case 400: return "Bad request" case _: return "Something's wrong with the internet" Patterns can look like unpacking assignments, and a pattern may be used to bind variables. In this example we match a tuple here, and the data point can be unpacked to its x- and y-coordinate.

Either would violate a longstanding expectation in Python, so the authors rejected both possibilities. Larry Hastings wondered about the special treatment being given to the "_" wildcard match. That symbol acts like a regular identifier, except in case statements, where it does not get bound (assigned to) for a match; it can also be used more than once in a case, which is not allowed for other match variables: match x: case (_, _): # match any tuple print(_) # _ will not have a value case (x, x): # ILLEGAL

This is Python 3.10’s most important new feature; the new functionality allows you to more easily control the flow of your programs by executing certain parts of code if conditions (or cases) are met. In this article, we’ll tell you everything you need to know about the match case statement in Python, which will allow you to have fine-grained control over how your programs execute.

December 7, 2024 - For example, in a pattern like case (a, *b), a matches the first element of the input tuple, while b captures the rest as another tuple. This feature allows for flexible matching of variable elements within a tuple, similar to how it works with ...

June 22, 2022 - Matching a list or tuple of length N involves writing a list of length N. And in my case, matching an abstract syntax tree involves writing code that looks like an abstract syntax tree.

When working with lists or tuples, you can match on their structure directly. For example: In this example, we destructure the coord variable directly within the case statements.

def func(subj: tuple[int | str, int | str]): match subj: case x, str(): reveal_type(subj) # tuple[int | str, str] case y: reveal_type(subj) # tuple[int | str, int] The tuple class derives from Sequence[T_co] where T_co is a covariant (non-variadic) type variable.

Python match...case allows tuples in cases, enabling structured pattern matching.

The tuple (0, y) destructures the point, matching any tuple where the first element is 0 (indicating it’s on the Y-axis) and binds the second element to y. The match keyword initiates the match case statement.

February 8, 2022 - Bug Report When using match on a tuple, mypy is unable to apply type narrowing when a case clause specifies the type of the elements of the tuple. To Reproduce Run this code through mypy: class MyClass: def say_boo(self) -> None: print("...