cmd 说语法无效。我找不到这个示例代码有什么问题答案

【问题标题】：cmd says invalid syntax. I can't find anything wrong with this sample codecmd 说语法无效。我找不到这个示例代码有什么问题
【发布时间】：2015-06-08 22:18:50
【问题描述】：

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。输出在 def main() 行显示无效语法。我找不到任何问题，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()

【问题讨论】：

请包含回溯
你是否混合了制表符和空格？
我使用了适当的缩进。
您添加的图像说错误是第61行，这是发布代码的第一行。您需要包含语法错误之前的代码，而不是其之后甚至没有被解析的所有内容。
我们开始了：正上方的语句缺少右括号。

标签： python syntax

【解决方案1】：

在urllib.request.retrieve(url, os.path.join(dest_dir, localname) 行上，您需要添加右括号。 :)

【讨论】：

【解决方案2】：

关闭括号。

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

语法错误几乎总是出现在解释器向您指出的语句的正上方。

【讨论】：