用于匹配电话号码的 Python 正则表达式

Question

I am newbie to Python regex , I need your help. I'm using the following regex to match phone numbers:

r'^\s*\(?([0-9]{3})[\)\-][\s]*?([0-9]{3})[-]?([0-9]{4})\s*$'

Apprantly it does pass most of cases but it does not fail some of the formats. Could someone clarify what I am doing wrong? I guess there is something wrong with space and parenthesis format in the first part of number.

It should pass these formats

'(404) 666-1111'
'(404) 6661111'
'404-666-1111'
'404-6661111'
'404666-1111'
'4046661111'
'  (404)   666-1111  '
'(404)666-1111  '
'  404-666-1111 '
'  404-6661111 '
' 4046661111'

and fail at these:

'+1 (404) 666-1111'
' ( 404)666-1111'
'404.666.1111'
'404 666-1111'
'404 666 1111'
'(404-666-1111'

Answer 1

The key challenge is making sure the parentheses match. Given the regular expressions can't count openers and closers, the usual way to do that part is provide two pattern alternative, one with parentheses and one without:

>>> bool(re.match(r'(\(\d{3}\))|\d{3}', '404'))
True
>>> bool(re.match(r'(\(\d{3}\))|\d{3}', '(404)'))
True
>>> bool(re.match(r'(\(\d{3}\))|\d{3}', '(404'))
False

Answer 2

The reason the whole numbers without any parenthesis or hyphen do not match is because at the beginning of the pattern, after 3 digits there is either a ) or - expected

^\s*\(?([0-9]{3})[)-]
                 ^^^^   

To match and not match all the examples, you might use

 ^\s*(?:\(\d{3}\)\s*|\d{3})-?\d{3}-?\d{4}\s*$

Explantion

• ^ Start of string
• \\s* Match 0+ whitespace chars
• (?: Non capture group
  • \\(\\d{3}\\)\\s* Match 3 digits between parenthesis and optional whitespace chars
  • | Or
  • \\d{3} Match 3 digits
• ) Close group
• -?\\d{3}-? Match 3 digits between optional hyphens
• \\d{4}\\s* Match 4 digits and optional whitespace chars
• $ End of string

Regex demo

Note that \\s could also match a newline

Answer 3

what you can do is to get rid off " " and then do regex try with "|"it means or Please note that this RegEx is incomplete, but the ide is that you can add more | in to this:

import re
numbersList=['(404) 666-1111' ,'(404) 6661111', '404-666-1111', '404-6661111' ,'404666-1111', '4046661111', '  (404)   666-1111  ' ,'(404)666-1111  ' ,'  404-666-1111 ', '  404-6661111 ', ' 4046661111' ]
regExStr="^\(\d{3}\) *\d+\-*\d+|^ *\d+\-\d+|^ *\d+|^ *\(\d{3}\)\d+\-\d+"
for number in numbersList:
    tmpStr=number.replace(" ", "")
    result = re.findall(regExStr, tmpStr)
    print(result)
    print("orig: " + number)