Increase the ordinal number at the beginning of each line

import re
f_in = open("C:/log/2016_06_29/male1.1.tgf")    
f_out = open("C:/log/2016_06_29/male1.0.tgf", "w")    

lines = f_in.readlines()

for line in lines:    
    num = int(re.match(r"\d+", line).group(0))
    num = num + 1
    pos = re.match("\d+",line).end()
    line = line[pos:]
    f_out.write("%d %s" % (num, line))    
print("increase done!")    
f_out.close()    
f_in.close()