python怎么下载视频

import os,import requests。
def download_video(url, file_path):
	try:
		headers = {"User-Agent": "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Maxthon/4.3.2.1000 Chrome/30.0.1599.101 Safari/537.36"}
		pre_content_length = 0
		# 循环接收视频数据
		while True:# 若文件已经存在，则断点续传，设置接收来需接收数据的位置    
			if os.path.exists(file_path):
				headers['Range'] = 'bytes=%d-' % os.path.getsize(file_path)
			res = requests.get(url, stream=True, headers=headers)
			content_length = int(res.headers['content-length'])
			# 若当前报文长度小于前次报文长度，或者已接收文件等于当前报文长度，则可以认为视频接收完成
			if content_length < pre_content_length or (os.path.exists(file_path) and os.path.getsize(file_path) >= content_length):
				break
			pre_content_length = content_length
			# 写入收到的视频数据
			with open(file_path, 'ab') as file:
				file.write(res.content)
				file.flush()
				print('receive data，file size : %d   total size:%d' % (os.path.getsize(file_path), content_length))
	except Exception as e:
		dic = {'url':url, 'file_path':file_path}
		print("下载失败:", dic)