leetcode--Python正则表达式解析Valid Phone nums

#!/usr/bin/env python
import os
import re
import sys
filename=sys.argv[1]
fd=open(filename,"r")

index=1
for row in fd.readlines() :
a=re.compile( r"^(?P<region>\d{3}-|\(\d{3}\) )(?P<numes>\d{3})-(?P<tails>\d{4})" )
b = a.match( row )
if b:
print( index  ,b.groups()  )
index=index+1

123-456-7890
(123) 456-7890
123 -
(123 )