Boundary-safe pagination math
Calculates page totals and item ranges explicitly, including empty collections and partial final pages.
Day 034 / APIs / Pagination
Pagination Simulator
/ Overview
A dependency-free Python CLI that calculates offset pagination, item bounds and an ellipsis-aware navigation window without requesting an API.
Offset pagination looks simple until empty collections, partial final pages, invalid page numbers and long navigation bars expose off-by-one mistakes. Testing those boundaries against a live API also adds unnecessary setup.
/ Provided servicesClear thinking.
Clear thinking.
Practical delivery.
Compact navigation model
Keeps first and last pages visible while centering a bounded page-number window around the current position.
Honest API boundary
Simulates pagination arithmetic only; it fetches no records and documents when cursor pagination may be more suitable.
/ Solution
Pagination Simulator validates four bounded integers and calculates total pages, one-based item bounds, zero-based offset, request limit, previous and next pages, and a stable navigation window. It produces readable or JSON output while making no network request and handling no record data.
/ Impact
Offset and limit calculation
One-based item bounds
Previous and next page states
Ellipsis-aware navigation
Empty and partial-page handling
Twelve standard-library tests included
Python standard library
Argparse, dataclasses and JSON provide the complete dependency-free command-line workflow.
API pagination
Models one-based pages, zero-based offsets, fixed limits, item ranges and navigation state.
Unittest
Twelve tests cover exact and partial pages, empty data, invalid pages, navigation windows and CLI JSON output.