Splitting a string based on a pattern in Python

Question

I have long strings such as

"123 - Footwear, 5678 - Apparel, Accessories & Luxury Goods, 9876 - Leisure Products"

and

"321 - Apparel & Accessories, 4321 - Apparel & Accessories > Handbags, Wallets & Cases, 187 - Apparel & Accessories > Shoes"

I want to split them based on the pattern "a number, a space, a dash, a space, some string until the next number, a space, a dash, a space or end of string". Notice that the string may contain commas, ampersands, '>' and other special characters, so splitting on them will not work. I think there is a way in Python to split based on regular expressions but I have trouble forming that.

I have a very introductory knowledge of regular expressions. I can form a regex for numbers, as well as for alphanumeric strings, but I don't know how to specify "take everything until the next number starts".

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Update: Expected output:

first case:

["123 - Footwear", "5678 - Apparel, Accessories & Luxury Goods", "9876 - Leisure Products"]

second case:

["321 - Apparel & Accessories", "4321 - Apparel & Accessories > Handbags, Wallets & Cases", "187 - Apparel & Accessories > Shoes"]

Answer 1

Here is the pattern, first there is some number so we use [0-9]+ followed by string and special characters like & - >, therefore we can use [a-zA-Z \-&>]+:

>>> str_ = "123 - Footwear, 5678 - Apparel, Accessories & Luxury Goods, 9876 - Leisure Products"
>>> re.findall(r'(?is)([0-9]+[a-zA-Z \-&>,]+)', str_)
['123 - Footwear, ',
 '5678 - Apparel, Accessories & Luxury Goods, ',
 '9876 - Leisure Products']

Another string you mentioned in OP

>>> str_ = "321 - Apparel & Accessories, 4321 - Apparel & Accessories > Handbags, Wallets & Cases, 187 - Apparel & Accessories > Shoes"
>>> re.findall(r'(?is)([0-9]+[a-zA-Z \-&>,]+)', str_)
['321 - Apparel & Accessories, ', 
 '4321 - Apparel & Accessories > Handbags, Wallets & Cases, ', 
 '187 - Apparel & Accessories > Shoes']

Answer 2

If numbers appear only at the beginning of each segment of strings, you can do:

import re
for s in "123 - Footwear, 5678 - Apparel, Accessories & Luxury Goods, 9876 - Leisure Products", "321 - Apparel & Accessories, 4321 - Apparel & Accessories > Handbags, Wallets & Cases, 187 - Apparel & Accessories > Shoes":
    print(re.findall(r'\d+\D+(?=,\s*\d|$)', s))

This outputs:

['123 - Footwear', '5678 - Apparel, Accessories & Luxury Goods', '9876 - Leisure Products']
['321 - Apparel & Accessories', '4321 - Apparel & Accessories > Handbags, Wallets & Cases', '187 - Apparel & Accessories > Shoes']

This regex pattern uses \d+ to match numbers first, then uses \D+ to match non-numbers, and uses lookahead pattern (?=,\s*\d|$) to make sure that the non-numbers stops at the point where it's followed by either a comma, some spaces and another number, or the end of the string, so that the resulting match won't include a trailing comma and a space.