我正在编写一个脚本来下载一组文件.我成功完成了这项工作并且工作正常.现在我尝试添加下载进度的动态打印输出.
对于小型下载(顺便说一下是.mp4文件),例如5MB,进展很有效,文件成功关闭,从而生成完整且有效的下载.mp4文件.对于较大的文件,如250MB及以上,它无法正常工作,我收到以下错误：
这是我的代码：
import urllib.request
import shutil
import os
import sys
import io
script_dir = os.path.dirname('C:/Users/Kenny/Desktop/')
rel_path = 'stupid_folder/video.mp4'
abs_file_path = os.path.join(script_dir,rel_path)
url = 'https://archive.org/download/SF145/SF145_512kb.mp4'
# Download the file from `url` and save it locally under `file_name`:
with urllib.request.urlopen(url) as response,open(abs_file_path,'wb') as out_file:
eventID = 123456
resp = urllib.request.urlopen(url)
length = resp.getheader('content-length')
if length:
length = int(length)
blocksize = max(4096,length//100)
else:
blocksize = 1000000 # just made something up
# print(length,blocksize)
buf = io.BytesIO()
size = 0
while True:
buf1 = resp.read(blocksize)
if not buf1:
break
buf.write(buf1)
size += len(buf1)
if length:
print('\r[{:.1f}%] Downloading: {}'.format(size/length*100,eventID),end='')#print('\rDownloading: {:.1f}%'.format(size/length*100),end='')
print()
shutil.copyfileobj(response,out_file)
这适用于小文件,但较大的文件我得到错误.现在,如果我注释掉进度指示器代码,我不会得到更大的文件错误：
with urllib.request.urlopen(url) as response,'wb') as out_file:
# eventID = 123456
#
# resp = urllib.request.urlopen(url)
# length = resp.getheader('content-length')
# if length:
# length = int(length)
# blocksize = max(4096,length//100)
# else:
# blocksize = 1000000 # just made something up
#
# # print(length,blocksize)
#
# buf = io.BytesIO()
# size = 0
# while True:
# buf1 = resp.read(blocksize)
# if not buf1:
# break
# buf.write(buf1)
# size += len(buf1)
# if length:
# print('\r[{:.1f}%] Downloading: {}'.format(size/length*100,end='')
# print()
shutil.copyfileobj(response,out_file)
有没有人有任何想法？这是我项目的最后一部分,我真的希望能够看到进展.再一次,这是Python 3.5.感谢您提供的任何帮助！
最佳答案
你打开你的网址两次,一次是响应,一次是响应.使用进度条的东西,你正在消耗数据,所以当使用copyfileobj复制文件时,数据是空的(也许这是不准确的,因为它适用于小文件,但你在这里做了两次,它可能是问题的原因)
with urllib.request.urlopen(url) as response,'wb') as out_file:
eventID = 123456
length = response.getheader('content-length')
if length:
length = int(length)
blocksize = max(4096,length//100)
else:
blocksize = 1000000 # just made something up
size = 0
while True:
buf1 = response.read(blocksize)
if not buf1:
break
out_file.write(buf1)
size += len(buf1)
if length:
print('\r[{:.1f}%] Downloading: {}'.format(size/length*100,end='')
print()
简化您的代码：
>只有一个urlopen,作为回应
>没有BytesIO,直接写入out_file