Question

我正在尝试运行一个程序，该程序从日志文件中收集url，并使用命令行参数将它们打印到新文件中。输出显示def main（）行的无效语法。我找不到任何错误，我正在使用python 3。

http://i.imgur.com/fIRDWoV.jpg?1

#!/usr/bin/python
# Copyright 2010 Google Inc.
# Licensed under the Apache License, Version 2.0
# http://www.apache.org/licenses/LICENSE-2.0

# Google's Python Class
# http://code.google.com/edu/languages/google-python-class/

import os
import re
import sys
import urllib.request

"""Logpuzzle exercise
Given an apache logfile, find the puzzle urls and download the images.

Here's what a puzzle url looks like:
10.254.254.28 - - [06/Aug/2007:00:13:48 -0700] "GET /~foo/puzzle-bar-aaab.jpg HTTP/1.0" 302 528 "-" "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6"
"""


def read_urls(filename):
  """Returns a list of the puzzle urls from the given log file,
  extracting the hostname from the filename itself.
  Screens out duplicate urls and returns the urls sorted into
  increasing order."""
  # +++your code here+++
  f = open(filename, 'rU')
  text = f.read()
  urls = re.findall('[\S]*puzzle[\S]*', text)
  urlList = []
  fullUrlList = []
  for url in urls:
    if not url in urlList:
      urlList.append(filename+url)
  fullUrlList = sorted(urlList)
  return fullUrlList




def download_images(img_urls, dest_dir):
  """Given the urls already in the correct order, downloads
  each image into the given directory.
  Gives the images local filenames img0, img1, and so on.
  Creates an index.html in the directory
  with an img tag to show each local image file.
  Creates the directory if necessary.
  """
  # +++your code here+++
  if not os.path.exists(dest_dir):
    os.makedirs(dest_dir)
  i = 0
  for url in img_urls:
    localname = 'img%d' %i
    urllib.request.retrieve(url, os.path.join(dest_dir, localname)




def main():
  args = sys.argv[1:]

  if not args:
    print ('usage: [--todir dir] logfile ')
    sys.exit(1)

  todir = None
  if args[0] == '--todir':
    todir = args[1]
    del args[0:2]


  img_urls = read_urls(args[0])

  if todir:
    download_images(img_urls, todir)
  else:
    print ('\n'.join(img_urls))

if __name__ == '__main__':
  main()

Answer 1

在urllib.request.retrieve(url, os.path.join(dest_dir, localname)行上，您需要添加一个右括号。 :)＆lt; 3

Answer 2

关闭括号。

urllib.request.retrieve(url, os.path.join(dest_dir, localname)
                                                              ^

语法错误几乎总是在解释器指出的语句正上方。

cmd表示语法无效。我发现这个示例代码没有任何问题

2 个答案: