First API request and response in Rest API - Mini Project: Build & Apply

First API request and response

📖 Scenario: You are building a simple program to get the current weather from a public API. This will help you learn how to make your first API request and see the response.

🎯 Goal: Learn how to send a GET request to a weather API and display the temperature from the response.

📋 What You'll Learn

Use the requests library to make an API call

Send a GET request to the URL https://api.weatherapi.com/v1/current.json?key=demo&q=London

Extract the temperature in Celsius from the JSON response

Print the temperature with a friendly message

💡 Why This Matters

🌍 Real World

APIs let programs get live data from websites and services. Weather apps use APIs to show current weather.

💼 Career

Knowing how to make API requests is a key skill for developers working with web services, mobile apps, or data integration.

1

Set up the API URL

Create a variable called url and set it to the string 'https://api.weatherapi.com/v1/current.json?key=demo&q=London'.

Rest API

# Create the API URL
# Your code here

Hint

Use a string variable to store the full API URL exactly as given.

2

Import requests and make the GET request

Import the requests library and create a variable called response that stores the result of requests.get(url).

Rest API

url = 'https://api.weatherapi.com/v1/current.json?key=demo&q=London'
# Import requests and get the response
# Your code here

Hint

Use import requests at the top. Then call requests.get(url) and save it in response.

3

Extract temperature from JSON response

Create a variable called data that stores the JSON content from response using response.json(). Then create a variable called temp_c that gets the temperature in Celsius from data['current']['temp_c'].

Rest API

import requests

url = 'https://api.weatherapi.com/v1/current.json?key=demo&q=London'
response = requests.get(url)
# Extract JSON data and temperature
# Your code here

Hint

Use response.json() to get the data. Then access the temperature with data['current']['temp_c'].

4

Print the temperature

Write a print statement that outputs: "The current temperature in London is {temp_c}°C." using an f-string.

Rest API

import requests

url = 'https://api.weatherapi.com/v1/current.json?key=demo&q=London'
response = requests.get(url)
data = response.json()
temp_c = data['current']['temp_c']
# Print the temperature with a message
# Your code here

Hint

Use print(f"The current temperature in London is {temp_c}°C.") to show the temperature.

Practice

1. What does a GET request in an API usually do?

easy

A. It asks the server to send data back.

B. It sends data to the server to be saved.

C. It deletes data from the server.

D. It updates existing data on the server.

Solution

1. Step 1: Understand the GET method

   The GET method is used to request data from a server without changing it.

2. Step 2: Identify the purpose of GET in API

   GET asks the server to send data back to the client.

3. Final Answer:

   It asks the server to send data back. -> Option A

4. Quick Check:

   GET = Request data [OK]

Hint: GET means get data from server, no changes made [OK]

Common Mistakes:

• Confusing GET with POST or DELETE methods
• Thinking GET changes data on server
• Mixing up request and response roles

2. Which of these is the correct way to write a simple GET request URL?

easy

A. POST /api/data HTTP/1.1

B. DELETE /api/data HTTP/1.1

C. GET /api/data HTTP/1.1

D. PUT /api/data HTTP/1.1

Solution

1. Step 1: Identify HTTP methods

   GET is the method used to request data, so the request line must start with GET.

2. Step 2: Check the request format

   The correct format is "GET /path HTTP/1.1" for a GET request.

3. Final Answer:

   GET /api/data HTTP/1.1 -> Option C

4. Quick Check:

   GET request line starts with GET [OK]

Hint: GET requests start with GET keyword in HTTP line [OK]

Common Mistakes:

• Using POST, DELETE, or PUT instead of GET
• Wrong HTTP version or missing method
• Confusing request line with response line

3. Given this API response snippet:

{"status":200,"data":{"name":"Alice","age":30}}

What does the status code 200 mean?

medium

A. The request was unauthorized.

B. The requested resource was not found.

C. There was a server error processing the request.

D. The request was successful and data is returned.

Solution

1. Step 1: Understand HTTP status codes

   Status code 200 means the request succeeded and the server returned the requested data.

2. Step 2: Match status code to meaning

   200 is standard for success; 404 means not found, 500 means server error, 401 means unauthorized.

3. Final Answer:

   The request was successful and data is returned. -> Option D

4. Quick Check:

   Status 200 = Success [OK]

Hint: 200 means OK, request worked fine [OK]

Common Mistakes:

• Confusing 200 with error codes like 404 or 500
• Thinking 200 means no data returned
• Mixing status codes with data content

4. You send a GET request to an API but get no response. Which of these is a likely cause?

medium

A. The server returned status code 200.

B. The API endpoint URL is incorrect or misspelled.

C. You used the GET method instead of POST.

D. Your request included a valid Authorization header.

Solution

1. Step 1: Check the URL correctness

   If the URL is wrong or misspelled, the server won't respond properly or may not be found.

2. Step 2: Evaluate other options

   Using GET instead of POST may cause wrong data but usually gets a response; status 200 means success; valid Authorization helps access.

3. Final Answer:

   The API endpoint URL is incorrect or misspelled. -> Option B

4. Quick Check:

   Wrong URL = No response [OK]

Hint: Check URL spelling first if no response [OK]

Common Mistakes:

• Assuming method error causes no response
• Ignoring URL typos
• Confusing status codes with no response

5. You want to get user info from an API at https://api.example.com/users/123. Which is the best way to check if your request worked?

hard

A. Check if the response status code is 200 and the data contains user details.

B. Check if the request method was POST and the server returned 404.

C. Check if the response status code is 500 and the data is empty.

D. Check if the URL contains the word 'users' and the method is DELETE.

Solution

1. Step 1: Understand success criteria for API requests

   A successful GET request returns status 200 and the expected data.

2. Step 2: Evaluate options for correctness

   POST method and 404 means not found; 500 means server error; DELETE method is for removing data, not getting it.

3. Final Answer:

   Check if the response status code is 200 and the data contains user details. -> Option A

4. Quick Check:

   Status 200 + data = success [OK]

Hint: Success = status 200 + expected data [OK]

Common Mistakes:

• Confusing POST with GET for data retrieval
• Ignoring status codes meaning
• Checking wrong HTTP methods for GET requests