Work With Network Response¶

Response Object¶

The result of doing a network request via Grab is a Response object.

You get a Response object as a result of calling to g.go, g.request and g.submit methods. You can also access the response object of a recent network query via the g.response attribute:

>>> from grab import Grab
>>> g = Grab()
>>> g.request('http://google.com')
<grab.doc.Document object at 0x2cff9f0>
>>> g.doc
<grab.doc.Document object at 0x2cff9f0>

You can find a full list of response attributes in the Response API document. Here are the most important things you should know:

body: original body contents of HTTP response
code: HTTP status of response
headers: HTTP headers of response
encoding: encoding of the response
cookies: cookies in the response
url: the URL of the response document. In case of some automatically processed redirect, the url attribute contains the final URL.
download_size: size of received data
upload_size: size of uploaded data except the HTTP headers

Now, a real example:

>>> from grab import Grab
>>> g = Grab()
>>> g.request('http://wikipedia.org')
<grab.doc.Document object at 0x1ff99f0>
>>> g.doc.body[:100]
'<!DOCTYPE html>\n<html lang="mul" dir="ltr">\n<head>\n<!-- Sysops: Please do not edit the main template'
>>> g.doc.code
200
>>> g.doc.headers['Content-Type']
'text/html; charset=utf-8'
>>> g.doc.encoding
'utf-8'
>>> g.doc.cookies
<CookieJar[Cookie(...), Cookie(..)]>
>>> g.doc.url
'http://www.wikipedia.org/'
>>> g.doc.download_size
11100.0
>>> g.doc.upload_size
0.0

Now let’s see some useful methods available in the response object:

unicode_body(): this method returns the response body converted to unicode
copy(): returns a clone of the response object
save(path): saves the response object to the given location
json: treats the response content as json-serialized data and de-serializes it into a python object. Actually, this is not a method, it is a property.
url_details(): return the result of calling urlparse.urlsplit with response.url as an argument.
query_param(name): extracts the value of the key argument from the query string of response.url.