import re
# Splitting will occurs only once, at '05', returned list will have length 2
print(re.split('d+', 'On 05th Jan 1999, at 11:02 AM', 1))
# 'Boy' and 'boy' will be treated same when flags = re.IGNORECASE
print(re.split('[a-f]+', 'Aey, Boy oh boy, come here', flags=re.IGNORECASE))
print(re.split('[a-f]+', 'Aey, Boy oh boy, come here'))