Match case statement with multiple 'or' conditions in each case

Question

Is there a way to assess whether a case statement variable is inside a particular list? Consider the following scenario. We have three lists:

a  = [1, 2, 3]
b  = [4, 5, 6]
c  = [7, 8, 9]

Then I want to check whether x is in each list. Something like this (of course this is a Syntax Error but I hope you get the point):

match x:
    case in a:
       return "132"
    case in b:
       return "564"
    case in c:
       return "798"

This can be easy with an if-else scenario. Nonetheless, focusing on the match-case, if one has many lists. And big lists, it would be a mundane task to write them like that:

match x:
    case 1 | 2 | 3:
       return "132"
    case 4 | 5 | 6:
       return "564"
    case 7 | 8 | 9:
       return "762"

Is there an easy way to check for multiple conditions for each case, without having to write them down?

I checked for duplicates, but I couldn't find them, I hope I don't miss something. Please be kind and let me know if there is a duplicate question.

Answer 1

As it seems cases accept a "guard" clause starting with Python 3.10, which you can use for this purpose:

match x:
  case w if w in a:
    # this was the "case in a" in the question
  case w if w in b:
    # this was the "case in b" in the question
  ...

the w here actually captures the value of x, part of the syntax here too, but it's more useful in some other fancy cases listed on the linked whatsnew page.