# lex_re3.py # # Regular expression rule matches empty string import sys if ".." not in sys.path: sys.path.insert(0,"..") import ply.lex as lex tokens = [ "PLUS", "MINUS", "NUMBER", "POUND", ] t_PLUS = r'\+' t_MINUS = r'-' t_NUMBER = r'(\d+)' t_POUND = r'#' def t_error(t): pass lex.lex()