Python Match

The match statement is used to perform different actions based on different conditions.

The Python Match Statement

Instead of writing many if..else statements, you can use the match statement.

The match statement selects one of many code blocks to be executed.

Syntax

match expression:
  case x:
    code block
  case y:
    code block
  case z:
    code block

This is how it works:

The match expression is evaluated once.
The value of the expression is compared with the values of each case.
If there is a match, the associated block of code is executed.

Example

The example below uses the weekday number to print the weekday name:

day = 4

match day:
  case 1:
    print("Monday")
  case 2:
    print("Tuesday")
  case 3:
    print("Wednesday")
  case 4:
    print("Thursday")
  case 5:
    print("Friday")
  case 6:
    print("Saturday")
  case 7:
    print("Sunday")

Default Value

Use the underscore character _ as the last case value if you want a code block to execute when there are no other matches:

Example

day = 4

match day:
  case 6:
    print("Today is Saturday")
  case 7:
    print("Today is Sunday")
  case _:
    print("Looking forward to the Weekend")

The value _ will always match, so it is important to place it as the last case to make it behave as a default case.

Combine Values

Use the pipe character | as an OR operator in the case evaluation to check for more than one value match in one case:

Example

day = 4

match day:
  case 1 | 2 | 3 | 4 | 5:
    print("Today is a weekday")
  case 6 | 7:
    print("I love weekends!")

If Statements as Guards

You can add if statements in the case evaluation as an extra condition-check:

Example

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")