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.