Python splitting but keeping the split string

Question

I find myself doing this pattern a lot:

new_url = season_url.split('cid=')[0] + 'cid='

Is there a more pythonic way to do this?

Answer 1

Something like this?

def truncate_after(s, needle):
    partition_pos = s.index(needle)+len(needle)
    return s[:partition_pos]

It could also return the other part if you wanted both pieces.