remove gibberish prefix from a string

a = "aajfkdfvf_valid_name0" 
b = "gdhdhsdsdeeeeex_valid_name1"

How do I remove the gibberish from my string before valid so that I have something like this –

valid_name0
valid_name1

>Solution :

If your strings always contains valid word, then you can try something like –

a = "aajfkdfvf_valid_name0" 
b = "gdhdhsdsdeeeeex_valid_name1"
for s in (a, b):
    print(s[s.rfind('valid'):])

So, even if the prefix contains _ or substring valid in it, the output will be correct. Though if your valid substring contains the word valid multiple times, then this will not work