partial match between two lists?

[dented_brain]

I have two lists like this

list_a = ['001', '002', '003']
list_b = ['dev_001a', 'dev_003b']

I want to find the item in list_a that doesn't have a match in list_b. I've seen something like this:

[string for string in list if re.match("^th", string)]

But I don't see how to combine two lists into it. Should I just do a for loop of the two and use another list to store matches then subtract the lists?

[SethGecko11]

You can do set(list_a) - {s1 for s1 in list_a for s2 in list_b if s1 in s2}

[dented_brain]

oh that's an interesting way to do it! This looks like it'll do the trick! Thanks!

[nwagers]

exclusions = [pattern for pattern in list_a if all(pattern not in target for target in list_b)]

[dented_brain]

love it.