Python代码优化：m3u8文件处理，替换media_并修复顺序问题

本文针对一段处理以'#YUMING|https'开头的m3u8文件的Python代码进行优化。代码中存在两个问题：

1. 对'media_'的替换部分存在错误: 代码原先将'media_'替换为一个完整的URL，但实际上'media_'只是一段文字，需要直接替换为新的URL地址。
2. 替换和删除的顺序错误: 代码先进行删除操作，然后进行替换，这会导致文件内容被改变，影响后续的替换结果。

以下提供修改后的代码：

import os
import requests

headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36',
    'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8',
    'Accept-Language': 'en-US,en;q=0.9,ja-JP;q=0.8,ja;q=0.7',
    'Cache-Control': 'no-cache',
    'Connection': 'keep-alive',
    'Pragma': 'no-cache',
    'Upgrade-Insecure-Requests': '1'
}

dir_path = input('请输入.m3u8文件所在目录的路径：')

for file_name in os.listdir(dir_path):
    if file_name.endswith('.m3u8'):
        print(f'处理文件: {file_name}')
        file_path = os.path.join(dir_path, file_name)
        with open(file_path, 'r') as f:
            lines = f.readlines()

        if '#YUMING|https' in lines[0]:
            url = lines[0][lines[0].index('https'):lines[0].index('/-/')+3]
            response = requests.post(url + 'playlist.m3u8', headers=headers)
            if response.status_code == 200:
                print('成功：' + str(response.status_code))
                new_url = response.url
                new_url = new_url[:new_url.index('playlist.m3u8')]

                # Replace all occurrences of 'media_' with the new URL
                new_lines = []
                for line in lines:
                    if 'media_' in line:
                        new_lines.append(line.replace('media_', new_url))
                    elif not line.startswith('#YUMING|https'):
                        new_lines.append(line)

                # Write the new lines back to the original file (except for the first line if it starts with '#YUMING|https')
                with open(file_path, 'w') as f:
                    for line in new_lines:
                        if not line.startswith('#YUMING|https'):
                            f.write(line)
            else:
                print('失效：' + str(response.status_code))

        else:
            if 'http' in lines[1]:
                url = lines[1][lines[1].index('http'):lines[1].index('/-/')+3]
            else:
                url = lines[8][lines[8].index('http'):lines[8].index('/-/')+3]

            response = requests.post(url + 'playlist.m3u8', headers=headers)
            if response.status_code == 200:
                print('成功：' + str(response.status_code))
                new_url = response.url
                new_url = new_url[:new_url.index('playlist.m3u8')]

                # Replace all occurrences of URLs between 'http' and '/-/' with the new URL
                new_lines = []
                for line in lines:
                    if 'http' in line and '/-/' in line:
                        new_lines.append(line[:line.index('http')] + new_url + line[line.index('/-/')+3:])
                    else:
                        new_lines.append(line)

                # Write the new lines back to the original file
                with open(file_path, 'w') as f:
                    for line in new_lines:
                        f.write(line)
            else:
                print('失效：' + str(response.status_code))

修改后的代码首先将'media_'替换为新的URL地址，然后将修改后的内容写入文件，最后再进行其他操作，确保代码逻辑正确。