#!/root/.pyenv/shims/python
# -*- coding: UTF-8 -*-
import sys
import requests
import threading
import datetime
#传入的命令行参数,要下载文件的url
url = sys.argv[1]
def Handler(start, end, url, filename):
headers = {'Range': 'bytes=%d-%d' % (start, end)}
r = requests.get(url, headers=headers, stream=True,timeout=5)
# 写入文件对应位置
with open(filename, "r+b") as fp:
fp.seek(start)
var = fp.tell()
fp.write(r.content)
def download_file(url, num_thread = 10):
r = requests.head(url)
try:
file_name = url.split('/')[-1]
file_size = int(r.headers['content-length']) # Content-Length获得文件主体的大小,当http服务器使用Connection:keep-alive时,不支持Content-Length
except:
print("检查URL,或不支持对线程下载")
return
# 创建一个和要下载文件一样大小的文件
fp = open(file_name, "wb")
fp.truncate(file_size)
fp.close()
# 启动多线程写文件
part = file_size // num_thread
# 如果不能整除,最后一块应该多几个字节
for i in range(num_thread):
start = part * i
if i == num_thread - 1: # 最后一块
end = file_size
else:
end = start + part
t = threading.Thread(target=Handler, kwargs={'start': start, 'end': end, 'url': url, 'filename': file_name})
t.setDaemon(True)
t.start()
# 等待所有线程下载完成
main_thread = threading.current_thread()
for t in threading.enumerate():
if t is main_thread:
continue
t.join()
print('%s 下载完成' % file_name)
if __name__ == '__main__':
start = datetime.datetime.now().replace(microsecond=0)
download_file(url)
end = datetime.datetime.now().replace(microsecond=0)
print("用时: ", end='')
print(end-start)