Cursor Tutorial

This tutorial describes details on pagination with Cursor objects.

Introduction

We use pagination a lot in Twitter API development. Iterating through timelines, user lists, direct messages, etc. In order to perform pagination we must supply a page/cursor parameter with each of our requests. The problem here is this requires a lot of boiler plate code just to manage the pagination loop. To help make pagination easier and require less code Tweepy has the Cursor object.

Old way vs Cursor way

First let’s demonstrate iterating the statues in the authenticated user’s timeline. Here is how we would do it the “old way” before Cursor object was introduced:

page = 1
while True:
    statuses = api.user_timeline(page=page)
    if statuses:
        for status in statuses:
            # process status here
            process_status(status)
    else:
        # All done
        break
    page += 1  # next page

As you can see we must manage the “page” parameter manually in our pagination loop. Now here is the version of the code using Cursor object:

for status in Cursor(api.user_timeline).items():
    # process status here
    process_status(status)

Now that looks much better! Cursor handles all the pagination work for us behind the scene so our code can now focus entirely on processing the results.

Passing parameters into the API method

What if you need to pass in parameters to the API method?

api.user_timeline(id="twitter")

Since we pass Cursor the callable, we can not pass the parameters directly into the method. Instead we pass the parameters into the Cursor constructor method:

Cursor(api.user_timeline, id="twitter")

Now Cursor will pass the parameter into the method for us when ever it makes a request.

Items or Pages

So far we have just demonstrated pagination iterating per an item. What if instead you want to process per a page of results? You would use the pages() method:

for page in Cursor(api.user_timeline).pages():
    # page is a list of statuses
    process_page(page)

Limits

What if you only want n items or pages returned? You pass into the items() or pages() methods the limit you want to impose.

# Only iterate through the first 200 statuses
for status in Cursor(api.user_timeline).items(200):
    process_status(status)

# Only iterate through the first 3 pages
for page in Cursor(api.user_timeline).pages(3):
    process_page(page)