# ----------------------------------------------------------------------------- # calclex.py # ----------------------------------------------------------------------------- tokens = ( 'NAME','NUMBER', 'PLUS','MINUS','TIMES','DIVIDE','EQUALS', 'LPAREN','RPAREN', ) # Tokens t_PLUS = r'\+' t_MINUS = r'-' t_TIMES = r'\*' t_DIVIDE = r'/' t_EQUALS = r'=' t_LPAREN = r'\(' t_RPAREN = r'\)' t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*' def t_NUMBER(t): r'\d+' try: t.value = int(t.value) except ValueError: print "Integer value too large", t.value t.value = 0 return t t_ignore = " \t" def t_newline(t): r'\n+' t.lineno += t.value.count("\n") def t_error(t): print "Illegal character '%s'" % t.value[0] t.skip(1) # Build the lexer import lex lex.lex()