Long-running operations (async responses) in Rest API - Mini Project: Build & Apply

Handling Long-Running Operations with Async Responses in REST API

📖 Scenario: You are building a REST API that processes large files. Since processing takes time, the API should respond immediately with a job ID and let the client check the job status later.

🎯 Goal: Create a simple REST API that starts a long-running job asynchronously, returns a job ID immediately, and allows clients to check the job status with that ID.

📋 What You'll Learn

Create a dictionary called jobs to store job statuses

Create a variable called job_counter starting at 1

Write a function start_job() that adds a new job with status 'running' and returns the job ID

Write a function check_status(job_id) that returns the status of the job

Print the job ID after starting a job

Print the status of a job when checked

💡 Why This Matters

🌍 Real World

Many web services handle tasks that take time, like file uploads or data processing. They respond immediately with a job ID and let users check progress later.

💼 Career

Understanding async responses and job tracking is important for backend developers, API designers, and anyone building scalable web services.

1

Create the initial data structure

Create a dictionary called jobs to store job statuses and a variable called job_counter set to 1.

Rest API

# Create a dictionary called jobs and a variable job_counter set to 1
# Your code here

Need a hint?

Use {} to create an empty dictionary and assign 1 to job_counter.

2

Add a function to start a job

Write a function called start_job() that uses the global job_counter, adds a new entry to jobs with status 'running', increments job_counter, and returns the job ID.

Rest API

jobs = {}
job_counter = 1

# Define start_job() function to add a new job with status 'running'
# Your code here

Need a hint?

Remember to use global job_counter inside the function to modify it.

3

Add a function to check job status

Write a function called check_status(job_id) that returns the status of the job from the jobs dictionary using the given job_id. If the job ID is not found, return 'not found'.

Rest API

jobs = {}
job_counter = 1

def start_job():
    global job_counter
    job_id = job_counter
    jobs[job_id] = 'running'
    job_counter += 1
    return job_id

# Define check_status(job_id) function to return job status or 'not found'
# Your code here

Need a hint?

Use the dictionary get() method to safely get the status or return 'not found'.

4

Start a job and print its status

Call start_job() and save the result in job_id. Then print the job ID with the message "Started job with ID: {job_id}". Next, call check_status(job_id) and print the status with the message "Status of job {job_id}: {status}".

Rest API

jobs = {}
job_counter = 1

def start_job():
    global job_counter
    job_id = job_counter
    jobs[job_id] = 'running'
    job_counter += 1
    return job_id

def check_status(job_id):
    return jobs.get(job_id, 'not found')

# Start a job, print the job ID, check the status, and print it
# Your code here

Need a hint?

Use print() with f-strings to show the messages exactly as described.