Python正则表达式匹配不起作用

Question

I have written below given code to match a string of fixed length of 10 which contains all digits.

import re
result=re.match("^d{10}$", u"5478512045")

But it returns None. I don't know why is it failing. Please correct me if I am doing anything wrong over here.

Answer 1

You are missing an escape \\ on the d control character. It should be:

result=re.match("^\d{10}$", u"5478512045")

Without the \\ before the d , your regex is trying to match a literal d string. By changing this to \\d you match against the special character for any decimal digit.