Question

Here in Google App Engines I got this code that would help fetch an HTML code of any web page by its URL:

from google.appengine.api import urlfetch
url = "http://www.google.com/"
result = urlfetch.fetch(url)
if result.status_code == 200:
doSomethingWithResult(result.content)

I don’t understand one thing here (among many other things, in fact) why it is suggested in this code to import urlfecth from google.appengine.api ? Does Python not have this command onits own?

Answer 1

google.appengine.api is a library that contains Google’s version of urlfetch class. Quoting from the manual:

The URL Fetch service uses Google’s
network infrastructure for efficiency
and scaling purposes.

Python has url retrieval classes in its standard library too, but those whould not be able to use the infrastructure that is available inside App Engine.

In short google.appengine.api urlfetch is more powerful, but there is nothing blocking from you from using Pythons own urllib either, that too is described in the manual page I linked above.