Wildcard match using Regex in Python

Question

I have to extract file ID from file links. The file link is similar to this example "\abc.xyz\folder1\folder2\folder3\folder5 \F-17-50021\OE \abc\xyz\file.xlsm" (bold part remains the same in every link). I decided to use regex to extract the file ID as there is a fixed pattern. I tried using the code below.

p = "Antartica"

re.search("n(.*)c",p).group(1)

It gives the output 'tarti' which is fine. I created a same regex to extract the file ID but it's not working.

p = r"\\abc.xyz\folder1\folder2\folder3\folder5\F-17-50021\OE\abc\xyz\file.xlsm"

re.search('\(.*)\OE', p).group(1)

I'm getting an error in mentioning "'NoneType' object has no attribute 'group'".

Please explain what is wrong in my code. How can I make it work?

TIA

I did that to accommodate the backslash inside the string. I will edit the post. — wickedpanda
– wickedpanda, Commented Dec 2, 2020 at 21:28
You are getting a None from re.search(...) this is the case when that doesn't find a pattern match. like @WiktorStribiżew stated you are looking for " characters in your pattern and they do not exist. Also consider using os.path.split() for a more robust cross-platform solution. — Tom Myddeltyn
– Tom Myddeltyn, Commented Dec 2, 2020 at 21:29

Ryszard Czech · Accepted Answer · 2020-12-02 21:28:00Z

1

Use

import re
 
p = r"\\abc.xyz\folder1\folder2\folder3\folder5\F-17-50021\OE\abc\xyz\file.xlsm"
match = re.search(r'\\([^\\]+)\\OE', p)
if match is not None:
    print(match.group(1))

See Python proof.

Results: F-17-50021

Explanation

--------------------------------------------------------------------------------
  \\                       '\'
--------------------------------------------------------------------------------
  (                        group and capture to \1:
--------------------------------------------------------------------------------
    [^\\]+                   any character except: '\\' (1 or more
                             times (matching the most amount
                             possible))
--------------------------------------------------------------------------------
  )                        end of \1
--------------------------------------------------------------------------------
  \\                       '\'
--------------------------------------------------------------------------------
  OE                       'OE'

answered Dec 2, 2020 at 21:28

Ryszard Czech

18.7k4 gold badges27 silver badges39 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

wickedpanda Over a year ago

this works! Could you please explain the regex a little?

Ryszard Czech Over a year ago

@wickedpanda See Explanation

wickedpanda Over a year ago

Thanks a lot Ryszard! :)

wickedpanda Over a year ago

I just found that in some links "\OE" has been replaced by "\FLD" or "\TURN" . Is it possible to add all three in the regex like an "or" statement '\OE" or "FLD" or "\TURN"?

Ryszard Czech Over a year ago

@wickedpanda Yes, r'\\([^\\]+)\\(?:OE|FLD|TURN)'

|

Collectives™ on Stack Overflow

Wildcard match using Regex in Python

1 Answer 1

7 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

7 Comments

Your Answer

Sign up or log in

Post as a guest

Related