在使用Python下载之前获取文件大小

import requests

url = "https://example.com/file.txt"
response = requests.head(url)

if response.status_code == 200:
    file_size = int(response.headers.get('Content-Length', 0))
    print(f"文件大小为：{file_size}字节")
else:
    print("无法获取文件大小")