understanding get_posts() parameters pages and post_per_page?

I don’t know if I’m misunderstanding facebook-scraper, my own code, or I’m seeing a bug. When I ran the code fragment:

for username in usernames:
    total_posts = 12
    if username == frequent_poster:
        total_posts = 24

    posts_per_page = 4

    pages = (total_posts + posts_per_page - 1) // posts_per_page

    print('')
    print('total_posts = %d, posts_per_page = %d, pages = %d' % (total_posts, posts_per_page, pages))

    posts = get_posts(username, cookies=cookie_file, pages=pages, extra_info=True,
                      options={'posts_per_page': posts_per_page, 'allow_extra_requests': False, 'HQ_images': False})

    print('Actual number of posts = %d' % (sum(1 for i in posts)))

I got the output:

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 9

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 9

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 30

...

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 30

total_posts = 24, posts_per_page = 4, pages = 6
Actual number of posts = 63

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 30

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 9

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 30

...

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 30

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 9

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 30

...

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 30

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 6

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 31

total_posts = 12, posts_per_page = 4, pages = 3
Actual number of posts = 30

I’m trying to understand how post extraction and its parameters work, and I expected the actual number of posts to be less than or equal to total_posts in each case. My goal is to make as few requests as possible.

What am I misunderstanding?

As always, I appreciate your help.

[curiousier-george]

Hmm, after commenting out

# set_user_agent("Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)")

I get 100 and everything seems to work. 😊

Thanks.

[neon-ninja]

The warning is safe to ignore