获取URL中两个相同字符之间的子字符串

from urllib.parse import urlparse

def get_substring_between_same_chars(url):
    parsed_url = urlparse(url)
    path = parsed_url.path

    start_index = None
    end_index = None

    for i in range(len(path)):
        if path[i] in path[i+1:]:
            start_index = i
            break

    if start_index is not None:
        for i in range(start_index+1, len(path)):
            if path[i] == path[start_index]:
                end_index = i
                break

    if start_index is not None and end_index is not None:
        substring = path[start_index+1:end_index]
        return substring
    else:
        return None

# 示例用法
url = "https://www.example.com/path/to/some/file.jpg"
substring = get_substring_between_same_chars(url)
print(substring)