Regular Expression to find data between 2 hyphens in file names

Question

I have a group of files with names of varying length in the format: aaaa-1234-filename.zip, aaaa-12345-filename-still-filename.zip, aaaa-123456-filename.zip, aaaa-1234567-filename-still-filename.zip.

I would like to strip off the first part of these filenames and remove everything up to and including the second -. I have attempted to go through PowerShell, but the Rename-Item -NewName only seems to be useful for removing the standardized portion of the name (e.g., aaaa-) and not the variable-length parts of the names.

Am I missing something in PowerShell or is there a better, easier way to perform this task?

Answer 1

There are a couple of ways to do this:

1. '\d+': matches all numbers,
2. '(?<=-).*?(?=-)': splits using - delimiter,
3. str.split('-'): splits using - delimiter.

Examples:

(1)

import re
s = 'aaaa-12345-filename-still-filename.zip'
nums = re.findall(r'\d+', s)[0]
# nums = '12345'

(2)

import re
s = 'aaaa-12345-filename-still-filename.zip'
nums = re.findall('(?<=-).*?(?=-)', s)[0]
# nums = '12345'

(3)

import re
s = 'aaaa-12345-filename-still-filename.zip'
nums = s.split('-')[1]
# nums = '12345'