Repository: yt-dlp/yt-dlp
File: yt_dlp/extractor/tencent.py (Python)

Code before:
import functools
import random
import re
import string
import time

from .common import InfoExtractor
from ..aes import aes_cbc_encrypt_bytes
from ..utils import (
    ExtractorError,
    float_or_none,
    determine_ext,
    int_or_none,
    js_to_json,
    traverse_obj,
    urljoin,
)


class TencentBaseIE(InfoExtractor):
    """Subclasses must set _API_URL, _APP_VERSION, _PLATFORM, _HOST, _REFERER"""

    def _check_api_response(self, api_response):
        code = api_response.get('code')
        msg = api_response.get('msg')
        if code != '0.0' and msg is not None:
            if msg in ('您所在区域暂无此内容版权（如设置VPN请关闭后重试）', 'This content is not available in your area due to copyright restrictions. Please choose other videos.'):
                self.raise_geo_restricted()
            raise ExtractorError(f'Tencent said: {msg}')
        return None

    def _get_ckey(self, video_id, url, guid):
        ua = self.get_param('http_headers')['User-Agent']

        payload = (f'{video_id}|{int(time.time())}|mg3c3b04ba|{self._APP_VERSION}|{guid}|'
                   f'{self._PLATFORM}|{url[:48]}|{ua.lower()[:48]}||Mozilla|Netscape|Windows x86_64|00|')

        return aes_cbc_encrypt_bytes(
            bytes(f'|{sum(map(ord, payload))}|{payload}', 'utf-8'),
            b'Ok\xda\xa3\x9e/\x8c\xb0\x7f^r-\x9e\xde\xf3\x14',
            b'\x01PJ\xf3V\xe6\x19\xcf.B\xbb\xa6\x8c?p\xf9',
            padding_mode='whitespace').hex().upper()

    def _get_video_api_response(self, video_url, video_id, series_id, subtitle_format, video_format, video_quality):
        guid = ''.join(random.choices(string.digits + string.ascii_lowercase, k=16))
        ckey = self._get_ckey(video_id, video_url, guid)
        query = {
            'vid': video_id,
            'cid': series_id,
            'cKey': ckey,
            'encryptVer': '8.1',

Review comment (suggestion):
Avoid variables only used once

```python
if api_response.get('code') != '0.0' and msg is not None:
```

Code after:
import functools
import random
import re
import string
import time

from .common import InfoExtractor
from ..aes import aes_cbc_encrypt_bytes
from ..utils import (
    ExtractorError,
    float_or_none,
    determine_ext,
    int_or_none,
    js_to_json,
    traverse_obj,
    urljoin,
)


class TencentBaseIE(InfoExtractor):
    """Subclasses must set _API_URL, _APP_VERSION, _PLATFORM, _HOST, _REFERER"""

    def _check_api_response(self, api_response):
        msg = api_response.get('msg')
        if api_response.get('code') != '0.0' and msg is not None:
            if msg in (
                '您所在区域暂无此内容版权（如设置VPN请关闭后重试）',
                'This content is not available in your area due to copyright restrictions. Please choose other videos.'
            ):
                self.raise_geo_restricted()
            raise ExtractorError(f'Tencent said: {msg}')

    def _get_ckey(self, video_id, url, guid):
        ua = self.get_param('http_headers')['User-Agent']

        payload = (f'{video_id}|{int(time.time())}|mg3c3b04ba|{self._APP_VERSION}|{guid}|'
                   f'{self._PLATFORM}|{url[:48]}|{ua.lower()[:48]}||Mozilla|Netscape|Windows x86_64|00|')

        return aes_cbc_encrypt_bytes(
            bytes(f'|{sum(map(ord, payload))}|{payload}', 'utf-8'),
            b'Ok\xda\xa3\x9e/\x8c\xb0\x7f^r-\x9e\xde\xf3\x14',
            b'\x01PJ\xf3V\xe6\x19\xcf.B\xbb\xa6\x8c?p\xf9',
            padding_mode='whitespace').hex().upper()

    def _get_video_api_response(self, video_url, video_id, series_id, subtitle_format, video_format, video_quality):
        guid = ''.join(random.choices(string.digits + string.ascii_lowercase, k=16))
        ckey = self._get_ckey(video_id, video_url, guid)
        query = {
            'vid': video_id,
            'cid': series_id,
            'cKey': ckey,