Because if you know the desired number of results in advance, fetch is faster than iterating over query when you are using cursors. You can read it on documentation: http://code.google.com/intl/en/appengine/docs/python/datastore/queries.html#Query_Cursors just above Limitations of Cursors.
On 4 jan, 17:46, Andreas <[email protected]> wrote: > good question! > > On Jan 4, 2012, at 12:53 PM, Kostya wrote: > > > > > > > > > Hi, > > > why I need to use the fetch() instance method if every query can > > return an iterator and I can access the results of a query by > > iterating over it: > > > authors = db.Query(Author).filter('name =', 'Kostya') > > for i in range(10): > > print authors[i].name > > > instead: > > > authors = db.Query(Author).filter('name =', 'Kostya') > > authors.fetch(10) > > for author in authors: > > print author.name > > > -- > > You received this message because you are subscribed to the Google Groups > > "Google App Engine" group. > > To post to this group, send email to [email protected]. > > To unsubscribe from this group, send email to > > [email protected]. > > For more options, visit this group > > athttp://groups.google.com/group/google-appengine?hl=en. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
