RegEx for matching URLs in Python

Question

I have this example string:

line = '[text] something - https://www.myurl.com/test1/ lorem ipsum https://www.myurl.com/test2/ - https://www.myurl.com/test3/ marker needle - some more text at the end'

I need to extract the path (without slashes) before "marker needle". The following works to list all paths:

print re.findall('https://www\\.myurl\\.com/(.+?)/', line)
# ['test1', 'test2', 'test3']

However, when I change it to only find the path I want (the one before "marker needle"), it gives a weird output:

print re.findall('https://www\\.myurl\\.com/(.+?)/ marker needle', line)
# ['test1/ lorem ipsum https://www.myurl.com/test2/ - https://www.myurl.com/test3']

My expected output:

test3

I have tried the same with re.search but the result is the same.

Answer 1

This expression has three capturing groups, where the second one has our desired output:

(https:\/\/www.myurl.com\/)([A-Za-z0-9-]+)(\/\smarker needle)

This tool helps us to modify/change the expression, if you wish.

RegEx Descriptive Graph

jex.im visualizes regular expressions:

Python Test

# -*- coding: UTF-8 -*-
import re

string = "[text] something - https://www.myurl.com/test1/ lorem ipsum https://www.myurl.com/test2/ - https://www.myurl.com/test3/ marker needle - some more text at the end"
expression = r'(https:\/\/www.myurl.com\/)([A-Za-z0-9-]+)(\/\smarker needle)'
match = re.search(expression, string)
if match:
    print("YAAAY! \"" + match.group(2) + "\" is a match 💚💚💚 ")
else: 
    print('🙀 Sorry! No matches!')

Output

YAAAY! "test3" is a match 💚💚💚

Performance Test

This snippet returns the runtime of a 1-million times for loop.

const repeat = 10;
const start = Date.now();

for (var i = repeat; i >= 0; i--) {
	const regex = /(.*)(https:\/\/www.myurl.com\/)([A-Za-z0-9-]+)(\/\smarker needle)(.*)/gm;
	const str = "[text] something - https://www.myurl.com/test1/ lorem ipsum https://www.myurl.com/test2/ - https://www.myurl.com/test3/ marker needle - some more text at the end";
	const subst = `$3`;

	var match = str.replace(regex, subst);
}

const end = Date.now() - start;
console.log("YAAAY! \"" + match + "\" is a match 💚💚💚 ");
console.log(end / 1000 + " is the runtime of " + repeat + " times benchmark test. 😳 ");