根据列表中的给定单词拆分字符串

Question

I am trying to find a way to split string based on given words only.

Also the new list should respect the word order from the initial string (text)

Few examples below:

def split_str_from_words(words, text):
    return ???

split_str_from_words(["hello", "world"], "helloworldhello")
split_str_from_words(["hello"], "helloworldhowareyouhello")
split_str_from_words(["hello", "how", "are", "you", "world"], "helloworldhowareyouhello")

Based on the 3 examples above, the function should return:

["hello", "world", "hello"]
["hello", "worldhowareyou", "hello"]
["hello", "world", "how", "are", "you", "hello"]

I have no clue how to do it ( I tried with functions such as split but so far nothing works as expected.

I have idea how to create my own algorithm but I wonder if there was any built-in functions that I can use for this case.

Thank you in advance.

EDIT:

So far I am able to detect all my words occurrence / position / word length

It could be really useful to keep the order of the words and slice strings.

import re

def split_str_from_words(words, text):
    for word in words:
        positions = [m.start() for m in re.finditer(word, text)]
        print(word, positions, len(positions), len(word))

    return ""

Answer 1

For the proposed example, re.split joining all words to be matched with | should do.

def split_str_from_words(l, s):
    m = re.split(rf"({'|'.join(l)})", s)
    return [i for i in m if i] # removes empty strings (improvements are welcome)

---

import re

split_str_from_words(["hello", "world"], "helloworldhello")
# ['hello', 'world', 'hello']

split_str_from_words(["hello"], "helloworldhowareyouhello")
# ['hello', 'worldhowareyou', 'hello']

split_str_from_words(["hello", "how", "are", "you", "world"], "helloworldhowareyouhello")
# ['hello', 'world', 'how', 'are', 'you', 'hello']