# http://stackoverflow.com/q/28353897/5290909
import re

text = "A\nB"
print("Text: '%s'\n---" % text)
patterns = [ "a", "a(?i)", "A.*B", "A(?s).*B", "A.*(?s)B"]

for p in patterns:
    match = re.search( p, text)
    print("Pattern: '%s'\t\tMatch: %s" % (p, match.span() if match else None))