image_url = soup.select('.image a')[0]['href'] IndexError: list index out of range

Question

当 URL 没有以 .png/.jpg 等图像扩展名结尾时，我使用了这段代码的一部分从 imgur 中检索图像。但是我收到了这些错误。请查看并提出修复建议：

https://github.com/asweigart/imgur-hosted-reddit-posted-downloader/blob/master/imgur-hosted-reddit-posted-downloader.py

import datetime
import praw
import re
import urllib
import requests
from bs4 import BeautifulSoup

sub = 'dog'
imgurUrlPattern = re.compile(r'(http://i.imgur.com/(.*))(\?.*)?')
r = praw.Reddit(user_agent = "download all images from a subreddit",
                user_site = "lamiastella")
already_done = []
#checkWords = ['i.imgur.com',  'jpg', 'png',]
check_words = ['jpg', 'png']

subreddit = r.get_subreddit(sub)
for submission in subreddit.get_hot(limit=10000):
        is_image = any(string in submission.url for string in check_words)
        print '[LOG] Getting url:  ' + submission.url
        if submission.id not in already_done and is_image:
           if submission.url.endswith('/'):
                modified_url = submission.url[:len(submission.url)-1]
                try:
                        urllib.urlretrieve(modified_url, '/home/jalal/computer_vision/image_retrieval/images/' + datetime.datetime.now().strftime('%y-%m-%d-%s') + modified_url[-4:])
                except IOError:
                        pass
           else:
                try:
                        urllib.urlretrieve(submission.url, '/home/jalal/computer_vision/image_retrieval/images/' + datetime.datetime.now().strftime('%y-%m-%d-%s') + submission.url[-4:])
                except IOError:
                        pass

           already_done.append(submission.id)
           print '[LOG] Done Getting ' + submission.url
           print('{0}: {1}'.format('submission id is', submission.id))
        elif 'http://imgur.com/' in submission.url:
                # This is an Imgur page with a single image.
                html_source = requests.get(submission.url).text # download the image's page
                soup = BeautifulSoup(html_source, "lxml")
                image_url = soup.select('.image a')[0]['href']
                if image_url.startswith('//'):
                        # if no schema is supplied in the url, prepend 'http:' to it
                        image_url = 'http:' + image_url
                        image_id = image_url[image_url.rfind('/') + 1:image_url.rfind('.')]
                        urllib.urlretrieve(image_url, '/home/jalal/computer_vision/image_retrieval/images/' + datetime.datetime.now().strftime('%y-%m-%d-%s') + image_url[-4:])

错误是：

[LOG] Getting url:  http://imgur.com/a/yOLjm
Traceback (most recent call last):
  File "download_images.py", line 43, in <module>
    image_url = soup.select('.image a')[0]['href']
IndexError: list index out of range

Answer 1

您选择错误 - 您需要 soup.select('img')[0]['src']

import datetime
import urllib
import requests
from bs4 import BeautifulSoup

url = 'http://imgur.com/gyUWtWP'

html_source = requests.get(url).text
soup = BeautifulSoup(html_source, "lxml")

image_url = soup.select('img')[0]['src']

if image_url.startswith('//'):
    image_url = 'http:' + image_url
    image_id = image_url[image_url.rfind('/') + 1:image_url.rfind('.')]

    urllib.urlretrieve(image_url, datetime.datetime.now().strftime('%y-%m-%d-%s') + image_url[-4:])

image_url = soup.select('.image a')[0]['href'] IndexError: list index out of range

image_url = soup.select('.image a')[0]['href'] IndexError: list index out of range

python

html

beautifulsoup

reddit

imgur