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.go('http://google.com')
<grab.response.Response object at 0x2cff9f0>
>>> g.response
<grab.response.Response 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 |
| charset: | charset 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. |
| name_lookup_time: | |
| time spent to resolve host name | |
| connect_time: | time spent to connect to remote server |
| total_time: | total time spent to complete the request |
| 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.go('http://wikipedia.org')
<grab.response.Response object at 0x1ff99f0>
>>> g.response.body[:100]
'<!DOCTYPE html>\n<html lang="mul" dir="ltr">\n<head>\n<!-- Sysops: Please do not edit the main template'
>>> g.response.code
200
>>> g.response.headers['Content-Type']
'text/html; charset=utf-8'
>>> g.response.charset
'utf-8'
>>> g.response.cookies
<grab.cookie.CookieManager object at 0x1f6b248>
>>> g.response.url
'http://www.wikipedia.org/'
>>> g.response.name_lookup_time
0.103931
>>> g.response.connect_time
0.221996
>>> g.response.total_time
0.7791399999999999
>>> g.response.download_size
11100.0
>>> g.response.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. | |