Recreate It in Code: requests + pytest with Shared State

The idea, in one line

The requests library sends the HTTP calls, and pytest runs your checks and tells you when one fails. Together they turn your Postman clicks into version-controlled code.

The moves you'll use

• Each verb is a function: requests.get, requests.post(url, json=payload), requests.put, requests.delete
• Read the reply with r.status_code and r.json()
• Send a query string with params= and headers with headers=
• Always add timeout= so a hung server can't freeze your whole suite

See it work

Real APIs are stateful: you create a record, then read, update and delete that same id. A requests.Session() keeps shared settings (like default headers) across calls, and a pytest fixture — reusable setup — hands that session to each test.

import requests, pytest

BASE = "https://jsonplaceholder.typicode.com"

@pytest.fixture
def session():
    s = requests.Session()
    s.headers.update({"Accept": "application/json"})
    return s  # reused across the calls in one test

def test_create_then_read(session):
    # CREATE
    r = session.post(f"{BASE}/posts",
                     json={"title": "qa", "userId": 1}, timeout=5)
    assert r.status_code == 201
    new_id = r.json()["id"]        # carry this id forward

    # READ the same resource
    r = session.get(f"{BASE}/posts/{new_id}", timeout=5)
    assert r.status_code == 200

Read it top to bottom: you created a record, grabbed the id it gave back, then used that id to read the record again. That create-then-reuse chain is the backbone of the whole suite.

Advanced — how pytest finds and reports

pytest auto-discovers any file named test_*.py and any function named test_, then runs your assert lines. When an assert fails, it prints both sides of the comparison — so a wrong status code reads like a ready-made bug report instead of a cryptic error.

Grounded in the official Requests quickstart and pytest docs