Python 从列表中下载文件（如果尚未下载）

我可以用c#实现，代码相当长

如果有人能告诉我如何通过python实现这一点，那就太酷了

伪代码是：

url: www.example.com/somefolder/filename1.pdf

1. load file into an array (file contains a url on each line)
2. if file e.g. filename1.pdf doesn't exist, download file

脚本可以采用以下布局：

/python-downloader/
/python-downloader/dl.py
/python-downloader/urls.txt
/python-downloader/downloaded/filename1.pdf

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虽然我假设

urls.txt

文件只包含url，但这应该可以做到这一点。不是

url:

前缀

import os
import urllib

DOWNLOADS_DIR = '/python-downloader/downloaded'

# For every line in the file
for url in open('urls.txt'):
    # Split on the rightmost / and take everything on the right side of that
    name = url.rsplit('/', 1)[-1]

    # Combine the name and the downloads directory to get the local filename
    filename = os.path.join(DOWNLOADS_DIR, name)

    # Download the file if it does not exist
    if not os.path.isfile(filename):
        urllib.urlretrieve(url, filename)

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Python中的代码更少，您可以使用如下内容：

import urllib2
improt os

url="http://.../"
# Translate url into a filename
filename = url.split('/')[-1]

if not os.path.exists(filename)
  outfile = open(filename, "w")
  outfile.write(urllib2.urlopen(url).read())
  outfile.close()

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下面是WoLpH针对Python3.3的脚本的一个稍加修改的版本

#!/usr/bin/python3.3
import os.path
import urllib.request

links = open('links.txt', 'r')
for link in links:
    link = link.strip()
    name = link.rsplit('/', 1)[-1]
    filename = os.path.join('downloads', name)

    if not os.path.isfile(filename):
        print('Downloading: ' + filename)
        try:
            urllib.request.urlretrieve(link, filename)
        except Exception as inst:
            print(inst)
            print('  Encountered unknown error. Continuing.')

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哇，这是惊人的简洁！我求求你看看这些炒作是怎么回事！谢谢你，伙计！使用os.path.basename（url），而不是在“/”上拆分。您应该将路径添加到脚本中。使用PATH=“./downloads”