只是想知道有什么方法可以在 Django 中检查 url 是否链接到有效图像。
问问题
3917 次
3 回答
4
使用requests和PIL来验证它实际上是一个有效的图像:
>>> import requests
>>> from PIL import Image
>>> from StringIO import StringIO
>>> r = requests.get('http://cdn.sstatic.net/stackoverflow/img/sprites.png')
>>> im = Image.open(StringIO(r.content))
>>> im
<PIL.PngImagePlugin.PngImageFile image mode=RGBA size=238x1073 at 0x2845EA8>
于 2012-06-29T14:18:52.320 回答
3
使用urllib2进行检查的简单方法。
>>> import urllib2
>>> url = 'https://www.google.com.pk/images/srpr/logo3w.png'
>>> try:
... f = urllib2.urlopen(urllib2.Request(url))
... imageFound = True
... except:
... imageFound = False
...
>>> imageFound
True
于 2012-06-29T12:57:13.607 回答
3
这是一个故障保护方法。首先,解析 url 以获取域和其余部分。
>>> from urllib.parse import urlparse
>>> url = 'http://example.com/random/folder/path.html'
>>> parse_object = urlparse(url)
>>> parse_object.netloc
'example.com'
>>> parse_object.path
'/random/folder/path.html'
>>> parse_object.scheme
'http'
现在,使用上面的信息来获取内容类型。使用parse_object.netloc
sstatic.netparse_object.path
代替,用硬编码路径代替。
>>> import httplib
>>> conn = httplib.HTTPConnection("sstatic.net")
>>> conn.request("HEAD", "/stackoverflow/img/favicon.ico")
>>> res = conn.getresponse()
>>> print res.getheaders()
[('content-length', '1150'), ('x-powered-by', 'ASP.NET'), ('accept-ranges', 'bytes'), ('last-modified', 'Mon, 02 Aug 2010 06:04:04 GMT'), ('etag', '"2187d82832cb1:0"'), ('cache-control', 'max-age=604800'), ('date', 'Sun, 12 Sep 2010 13:39:26 GMT'), ('content-type', 'image/x-icon')]
这告诉您它是 1150 字节的图像(图像/* mime-type)。足够的信息让您决定是否要获取完整的资源。
编辑
对于缩短的 url,比如http://goo.gl/IwruD
指向 的http://ubuntu.icafebusiness.com/images/ubuntugui2.jpg
,在你得到的响应中,有一个额外的参数叫做'location'
.
这就是我所说的:
>>> import httplib
>>> conn = httplib.HTTPConnection("goo.gl")
>>> conn.request("HEAD", "/IwruD")
>>> res = conn.getresponse()
>>> print res.getheaders()
[('x-xss-protection', '1; mode=block'),
('x-content-type-options', 'nosniff'),
('transfer-encoding', 'chunked'),
('age', '64'),
('expires', 'Mon, 01 Jan 1990 00:00:00 GMT'),
('server', 'GSE'),
('location', 'http://ubuntu.icafebusiness.com/images/ubuntugui2.jpg'),
('pragma', 'no-cache'),
('cache-control', 'no-cache, no-store, max-age=0, must-revalidate'),
('date', 'Sat, 30 Jun 2012 08:52:15 GMT'),
('x-frame-options', 'SAMEORIGIN'),
('content-type', 'text/html; charset=UTF-8')]
在直接网址中,您找不到它。
>>> import httplib
>>> conn = httplib.HTTPConnection("ubuntu.icafebusiness.com")
>>> conn.request("HEAD", "/images/ubuntugui2.jpg")
>>> res = conn.getresponse()
>>> print res.getheaders()
[('content-length', '78603'), ('accept-ranges', 'bytes'), ('server', 'Apache'), ('last-modified', 'Sat, 16 Aug 2008 01:36:17 GMT'), ('etag', '"1fb8277-1330b-45489c3ad2640"'), ('date', 'Sat, 30 Jun 2012 08:55:46 GMT'), ('content-type', 'image/jpeg')]
您可以使用简单的代码查找:
>>> r = res.getheaders()
>>> redirected = False
>>> for e in r:
>>> if(e[0] == 'location'):
>>> redirected = e
>>>
>>> if(redirected != False):
>>> print redirected[1]
'http://ubuntu.icafebusiness.com/images/ubuntugui2.jpg'
于 2012-06-29T13:13:53.123 回答