I need a python regular expression to check if a word is present in a string. The string is separated by commas, potentially.

So for example,

line = 'This,is,a,sample,string'

I want to search based on "sample", this would return true. I am crappy with reg ex, so when I looked at the python docs, I saw something like

import re
re.match(r'sample', line)

But I don't know why there was an 'r' before the text to be matched. Can someone help me with the regular expression?

Are you sure you need a regex? It seems that you only need to know if a word is present in a string, so you can do:

>>> line = 'This,is,a,sample,string'
>>> "sample" in lineTrue