import requests

url = "https://er-sycdn.kuwo.cn/5a1fdd7e1178a867af57c6b0ba576889/69468dc3/resource/30106/trackmedia/F000000bYDlc2XxKLs.flac"

headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36',
    'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
    'Accept-Language': 'en-US,en;q=0.5',
    'Accept-Encoding': 'gzip, deflate',
    'Connection': 'keep-alive',
    'Upgrade-Insecure-Requests': '1',
}

total_length = int(requests.get(url, stream=True, headers=headers).headers.get('content-length'))

print(total_length)