Python - Match/Case

Python `match-case` statement take an expression and compares it against a set of patterns. When a pattern matches the expression, the corresponding block of code is executed.

match expression:
    case pattern_1:
        # tasks...
    case pattern_2:
        # tasks...
    case _: # <- default
        # tasks...

In Python, the default case is represented by an underscore `_`.

fruit = 'papaya'
price = None

match fruit:
  case 'apple':
    print('apple: $0.14')
    price = 0.14
  case 'orange':
    print('orange: $0.17')
    price = 0.17
  case 'pear':
    print('pear: $0.09')
    price = 0.09
  case _:
     print('No price-label')

Case Patterns

• case `OR`

  num = 2
  
  match num:
    case 2 | 3 | 5 | 7:
      print('prime!')
    case 1 | 4 | 6 | 8 | 9:
      print('no-prime!')
  

  name = "John Doe"
  
  match name:
    case "Peter Parker" | "Marc Spector":
      print("Hello! You're a hero, right?")
    case "John Doe" | "Jane Doe":
      print("So... What is your real name?")
    case "Felipe Izolan":
      print("Hey! that's me!")
  

  The `|` symbol means `OR`.

• case `if`

  num = 3
  
  match num:
    case num if num > 0:
      print('positive!')
    case num if num < 0:
      print('negative!')
    case _:
      print('zero')