Python下载Zip文件损坏

Question

So, I've been trying to make a simple downloader that downloads my zip file.

Code looks like this:

import urllib2
import os
import shutil

url = "https://dl.dropbox.com/u/29251693/CreeperCraft.zip"

file_name = url.split('/')[-1]
u = urllib2.urlopen(url)
f = open('c:\CreeperCraft.zip', 'w+')
meta = u.info()

file_size = int(meta.getheaders("Content-Length")[0])
print "Downloading: %s Bytes: %s" % (file_name, file_size)

file_size_dl = 0
block_sz = 8192
while True:
    buffer = u.read(block_sz)
    if not buffer:
        break

    file_size_dl += len(buffer)
    f.write(buffer)
    status = r"%10d  [%3.2f%%]" % (file_size_dl, file_size_dl * 100. / file_size)
    status = status + chr(8)*(len(status)+1)
    print status,

f.close()

And the problem is, it downloads the file to the correct path, but when I open the file, its damaged, only 1 picture appears and when you click on it, it says File Damaged .

Please help.

Answer 1

f = open('c:\CreeperCraft.zip', 'wb+')

Answer 2

You are using "w+" as flag, Python opens the file in text mode:

Python on Windows makes a distinction between text and binary files; the end-of-line characters in text files are automatically altered slightly when data is read or written. This behind-the-scenes modification to file data is fine for ASCII text files, but it'll corrupt binary data like that in JPEG or EXE files.

http://docs.python.org/tutorial/inputoutput.html#reading-and-writing-files

Also, note that you should escape the backslash or use raw strings, therefore use open('c:\\\\CreeperCraft.zip', 'wb+') .

I also would recommend that you do not copy raw byte strings by hand, but use shutil.copyfileobj - it makes your code more compact and easier to understand. I also like to use the with statement that automatically cleans up resources (ie that closes files:

import urllib2, shutil

url = "https://dl.dropbox.com/u/29251693/CreeperCraft.zip"
with urllib2.urlopen(url) as source, open('c:\CreeperCraft.zip', 'w+b') as target:
  shutil.copyfileobj(source, target)

Answer 3

import posixpath
import sys
import urlparse
import urllib

url = "https://dl.dropbox.com/u/29251693/CreeperCraft.zip"
filename = posixpath.basename(urlparse.urlsplit(url).path)
def print_download_status(block_count, block_size, total_size):
    sys.stderr.write('\r%10s bytes of %s' % (block_count*block_size, total_size))
filename, headers = urllib.urlretrieve(url, filename, print_download_status)