More readable way to compare variable to list of values in if statement? [duplicate]

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• Is there a shorter way to write compound 'if' conditions? [duplicate] 12 answers

How can I compare a variable to a list of values of the same type in an if statement and make it readable and clean?

For example, I have the following, but there are a lot of values, and I want to make it more readable.

if ((lst->type == 'p' || lst->type == 'x' || lst->type == 'X' ||
    lst->type == 'o' || lst->type == 'O' || (lst->type == 'd' ||
    lst->type == 'i' || lst->type == 'D'))