import re

re_1 = r'hello!*'
re_2 = r'hello!* +there'
re_3 = r'(\+|\-|\*|\/)'
re_4 = r'\-?[0-9]+'
re_5 = r'\"([a-z]+ *)+\"'
re_6 = r'\"([[a-z]|\\.]+ *)+\"'