在Python中查找字符串中的所有子字符串，我如何才能使其更好？

def find_substrings(string, substring):
    start = 0
    indexes = []
    while True:
        index = string.find(substring, start)
        if index == -1:
            break
        indexes.append(index)
        start = index + 1
    return indexes

string = "Hello, Hello, Hello, World!"
substring = "Hello"
indexes = find_substrings(string, substring)
print(indexes)  # 输出：[0, 7, 14]

import re

def find_substrings(string, substring):
    pattern = re.compile(f'(?={substring})')
    indexes = [match.start() for match in re.finditer(pattern, string)]
    return indexes

string = "Hello, Hello, Hello, World!"
substring = "Hello"
indexes = find_substrings(string, substring)
print(indexes)  # 输出：[0, 7, 14]