Extracting dates out of python array of string using regex

Question

I'm trying to extract dates out of a string using python. The date is in the format mm-dd-yyyy. So I know the regex should be something like /d{2}-/d{2}-/d{4}. However when I try and iterate over the array below I am not able to extract the dates out of the string.

import re 
logs = ["First entry to journal logs. (01-01-2015)", "Last entry to journal logs 07-01-2016"]
for i in logs:
    m = re.match("/d{2}-/d{2}-/d{4}",i)
    print m.group(0)

I haven't work with re before so not sure if I'm using it properly.

The regex escaping symbol is ``\``, not `/`. To extract all matches [use `re.findall`](https://stackoverflow.com/questions/4697882/how-can-i-find-all-matches-to-a-regular-expression-in-python). — Wiktor Stribiżew, Nov 29 '17 at 15:00
I tried the \d{2}-\d{2}-\d{4} but I'm string note getting any values — codeBarer, Nov 29 '17 at 15:05
@codeBarer put an `r` before the string so that it's `r"\d{2}-\d{2}-\d{4}"` — ctwheels, Nov 29 '17 at 15:06
@codeBarer you also want to use `search` instead of `match`. The latter is anchored at the start of the string such that your regex becomes `^\d{2}-\d{2}-\d{4}`, while the former searches anywhere in the string — ctwheels, Nov 29 '17 at 15:14

score 2 · Answer 1 · answered Nov 29 '17 at 15:59

2

This should do the trick:

import re

s = ["First entry to journal logs. (01-01-2015)", "Last entry to journal logs 07-01-2016"]

print([re.findall(r'\d{2}\-\d{2}\-\d{4}', i) for i in s])

Yields:

[['01-01-2015'], ['07-01-2016']]

answered Nov 29 '17 at 15:59

rahlf23

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score 1 · Accepted Answer · answered Nov 29 '17 at 15:46

You can't use match to search inside a text, If you use match you need to match from Initial position to Final position, to search inside a text use search:

#!/usr/bin/python3
# -*- coding: utf-8 -*-

import re
logs = ["First entry to journal logs. (01-01-2015)", "Last entry to journal logs 07-01-2016"]
for i in logs:
    m = re.search("[0-9]{2}\-[0-9]{2}\-[0-9]{4}",i)
    if m:
        print m.group(0)

Output:

01-01-2015
07-01-2016

Extracting dates out of python array of string using regex

2 Answers2