python - 如何查看下载过程？

Question

在使用 urllib.request.urlretrieve 时，我想知道是否有办法查看控制台打印的下载状态以及文件大小等信息？

这是我测试的代码:

#!/usr/bin/env python3.5.2

import urllib.request
import os


# make sure to change the directory before you test the code
directory = r'C:\Users\SalahGfx\Desktop\Downloads'

url = 'https://upload.wikimedia.org/wikipedia/en/d/d8/C4D_Logo.png' 

def get_name_path():
    image_name = url.split('/')[-1]
    return os.path.join(directory, image_name)

urllib.request.urlretrieve(url, get_name_path())

print('The Image has been downloaded!')

Answer 1

没有内置任何东西。您必须自己编写。幸运的是，这并不难。您只需要从标题中读取内容的长度，然后按 block 读取响应。这是代码

import urllib2, sys

def chunk_report(bytes_so_far, chunk_size, total_size):
    percent = float(bytes_so_far) / total_size
    percent = round(percent*100, 2)
    sys.stdout.write("Downloaded %d of %d bytes (%0.2f%%)\r" % 
                     (bytes_so_far, total_size, percent))

    if bytes_so_far >= total_size:
       sys.stdout.write('\n')

def chunk_read(response, chunk_size=8192, report_hook=None):
    total_size = response.info().getheader('Content-Length').strip()
    total_size = int(total_size)
    bytes_so_far = 0

    while 1:
       chunk = response.read(chunk_size)
       bytes_so_far += len(chunk)

       if not chunk:
          break

       if report_hook:
          report_hook(bytes_so_far, chunk_size, total_size)

    return bytes_so_far

def get_name_path():
    image_name = url.split('/')[-1]
    return os.path.join(directory, image_name)

# make sure to change the directory before you test the code
directory = r'C:\Users\SalahGfx\Desktop\Downloads'

url = 'https://upload.wikimedia.org/wikipedia/en/d/d8/C4D_Logo.png' 

response = urllib.request.urlopen(url, get_name_path())
chunk_read(response, report_hook=chunk_report)

重要的是要注意我使用了 urllib.request.urlopen 因为 urllib2.request.retrieve 被认为是 legacy并将很快被弃用。