Python无法使用正则表达式解析日期

Question

I have a program in which the user can enter a string and have the date in the string. I am using RegEx to match \\d+\\/\\d+\\/\\d+ to extract the date from the string but for some reason in my test case, only the last entry is able to work

import datetime
import re
dateList = []
dates = ["Foo (8/15/15) Bar", "(8/15/15)", "8/15/15"]
reg = re.compile('(\d+\/\d+\/\d+)')
for date in dates:
    matching = reg.match(date)
    if matching is not None:
        print date, matching.group(1)
    else:
        print date, "is not valid date"

returns

Foo (8/15/15) Bar is not valid date
(8/15/15) is not valid date
8/15/15 8/15/15

Is there something wrong with my RegEx? I tested it with RegEx101.com and it seemed to work fine

Answer 1

if you are looking for a partial match of the regex, use search:

import datetime
import re
dateList = []
dates = ["Foo (8/15/15) Bar", "(8/15/15)", "8/15/15"]
reg = re.compile('([0-9]+/[0-9]+/[0-9]+)')
for date in dates:
    matching = reg.search(date)  # <- .search instead of .match
    if matching is not None:
        print( date, matching.group(1) )
    else:
        print( date, "is not valid date" )

Answer 2

You are looking for search() , not match() .

date_re = re.compile('([0-9]{2})/([0-9]{2})/([0-9]{2})')
e = date_re.match('foo 01/02/13')
# e is None
e = date_re.search('foo 01/02/13')
# e.groups() == ('01', '02', '13')

Do not use \\d where you expect the ASCII 0-9 digits because there are many strange things matched by the Unicode version of \\d .