To do a case-insensitive search, you need to convert your target string and strings in the list to either lowercase or uppercase.
Here is an example:
>>> aa=['hello','How','Are','you']>>> 'Are'.lower() in [i.lower() for i in aa]True>>> 'How'.lower() in [i.lower() for i in aa]True>>> 'hoW'.lower() in [i.lower() for i in aa]True>>> 'HeLLo'.lower() in [i.lower() for i in aa]True