Get text between last forward slash and then before first hyphen

Question

I need to parse a URL, and get 1585710 from :

http://www.example.com/0/100013573/1585710-key-description-goes-here

So that means it's between the last / and before the first -

I have very little experience with regex, it's a really hard concept for me to understand.

Any help or assistance would be much appreciated

Edit: Using Python.

Solution 1

Use the below regex and get the number from group index 1.

^.*\/([^-]*)-.*$

DEMO

Code:

>>> import re
>>> s = "http://www.example.com/0/100013573/1585710-key-description-goes-here"
>>> m = re.search(r'^.*\/([^-]*)-.*$', s, re.M)
>>> m
<_sre.SRE_Match object at 0x7f8a51f07558>
>>> m.group(1)
'1585710'
>>> m = re.search(r'.*\/([^-]*)-.*', s)
>>> m.group(1)
'1585710'
>>> m = re.search(r'.*\/([^-]*)', s)
>>> m.group(1)
'1585710'

Explanation:

• .*\/ Matches all the characters upto the last / symbol.
• ([^-]*) Captures any character but not of - zero or more times.
• -.* Matches all the remaining characters.
• group(1) contains the characters which are captured by the first capturing group. Printing the group(1) will give the desired result.

Solution 2

Well, if you need to find any strings between a / and a -, you could simply do:

/.*-

Since . is any char, and * is any amount. However, this poses a problem, because you could get the whole /www.example.com/0/100013573/1585710-key-description-goes, which is between / and a -. So, what you need to do is to search for anything that is not a / and -:

/[^/-]*-

^ means no, and anything between [] is, roughly, an OR list.

Hope that helps.

EDIT: No, it doesn't help, as user rici mentioned, when you have a - in your url name (as in www.lala-lele.com).

To make sure is the last / you got, you can match the rest of your string, making sure it doesn't have any / in it until the end ($), as in:

/[^/-]*-[^/]*$

And, to get just the string inside it, you can:

/\([^/-]*\)-[^/]*$

Since \( and \) specify what you want as the output of your regex.

Solution 3

You can use matching groups in order to extract the number with the regex \/(\d+)-:

import re
s = 'http://www.example.com/0/100013573/1585710-key-description-goes-here'
m = re.search(r'\/(\d+)-', s)
print m.group(1) # 1585710

Check out the Fiddler

Comments

[rici]

OP wants the string between the last slash and the next dash. Your regex will fail, for example, on /www.best-example.com/0/100013573/1585710-key-description-go‌​es