Working with APIs

What is an API?

An API (Application Programming Interface) is like a waiter at a restaurant. You tell it what you want, and it brings you the data. But APIs do more than just fetch information. They’re the bridges that connect your code to other systems. With APIs, you can:

Pull customer data from your CRM (Salesforce, HubSpot)
Get order information from Shopify or WooCommerce
Send messages through Slack or email services
Use AI models from OpenAI or Anthropic

In the context of AI, APIs are essential. They let you connect AI capabilities to real business data and systems.

`requests` Module

The requests module is a popular third-party Python library used to send HTTP requests. It simplifies communication with web servers and REST APIs.

Install the library using:
pip install requests

Common HTTP Methods

Method	Purpose
`GET`	Retrieve data from a server
`POST`	Send new data to a server
`PUT`	Update existing data
`DELETE`	Remove data from a server

Example: GET Request

import requests

response = requests.get("https://jsonplaceholder.typicode.com/posts/1")

print(response.status_code)
print(response.json())

Example: POST Request

import requests

data = {
    "title": "Python",
    "body": "Learning Requests",
    "userId": 1
}

response = requests.post(
    "https://jsonplaceholder.typicode.com/posts",
    json=data
)

print(response.status_code)
print(response.json())

Useful Response Attributes

Attribute	Description
`response.status_code`	HTTP status code
`response.text`	Response as plain text
`response.json()`	Response as JSON
`response.headers`	Response headers
`response.content`	Response as bytes

Common Status Codes

Code	Meaning
`200`	OK
`201`	Created
`400`	Bad Request
`401`	Unauthorized
`404`	Not Found
`500`	Internal Server Error

Let’s get real weather data using a free weather API:

import requests

# We need coordinates to get weather data
latitude = 48.85   # Paris latitude
longitude = 2.35   # Paris longitude

# Build the API URL with our parameters
url = f"https://api.open-meteo.com/v1/forecast?latitude={latitude}&longitude={longitude}&current=temperature_2m"

# Make the request
response = requests.get(url)
data = response.json()

print(data)

First install requests: pip install requests

Understanding the response

The API sends back data in JSON format (like a Python dictionary):

{
    'latitude': 48.84,
    'longitude': 2.36,
    'timezone': 'GMT',
    'elevation': 46.0,
    'current_units': {
        'temperature_2m': '°C'
    },
    'current': {
        'time': '2025-08-01T08:30',
        'temperature_2m': 20.0
    }
}

The temperature is nested inside current, so to get it:

temperature = data['current']['temperature_2m']
print(f"Temperature in Paris: {temperature}°C")
# Output: Temperature in Paris: 20.0°C

What is JSON? JSON (JavaScript Object Notation) is just a way to structure data, similar to CSV or Excel files. While CSV stores data in rows and columns, JSON uses key-value pairs like Python dictionaries.

Extract what you need

Now you can pull out specific information:

import requests

def get_weather(latitude, longitude):
    response = requests.get(f"https://api.open-meteo.com/v1/forecast?latitude={latitude}&longitude={longitude}&current=temperature_2m,wind_speed_10m")
    data = response.json()
    return data['current']['temperature_2m']

# Get temperature for different cities
paris_temp = get_weather(48.85, 2.35)
london_temp = get_weather(51.50, -0.12)
tokyo_temp = get_weather(35.68, 139.69)

print(f"Paris: {paris_temp}°C")
print(f"London: {london_temp}°C")
print(f"Tokyo: {tokyo_temp}°C")

How it works

You send a request to the API’s URL with parameters (like coordinates)
The API processes your request and finds the data
You receive JSON data back with the information
You extract the specific parts you need

Practice & Exercises

To reinforce what you’ve learned in this section (making API requests, reading JSON response payloads, extracting nested properties, and querying coordinates dynamically), practice with these interactive notebooks:

Follow-Along Practice

Practice submitting coordinate parameters to weather APIs using requests, extracting nested dictionary properties, and writing query wrappers to compare temperature statistics.💻 VS Code | 🚀 Colab | 📥 Download

Practice Exercises

Test your knowledge with hands-on exercises on querying Indian cities, writing get_weather_details for temperature/wind outputs, and adding exception handling to API calls.💻 VS Code | 🚀 Colab | 📥 Download

What’s next?

Now that you know how to connect to web APIs, let’s learn how to store API keys and database credentials securely using environment variables.

Working with Environment Variables

Learn to manage secrets with .env files

Functions

Classes

Error handling

Modules & Packages

Extending Python

What is an API?

`requests` Module

Common HTTP Methods

Example: GET Request

Example: POST Request

Useful Response Attributes

Common Status Codes

Let’s get real weather data using a free weather API:

Understanding the response

Extract what you need

How it works

Practice & Exercises

Follow-Along Practice

Practice Exercises

What’s next?

Working with Environment Variables

​What is an API?

​requests Module

​Common HTTP Methods

​Example: GET Request

​Example: POST Request

​Useful Response Attributes

​Common Status Codes

​Let’s get real weather data using a free weather API:

​Understanding the response

​Extract what you need

​How it works

​Practice & Exercises

Follow-Along Practice

Practice Exercises

​What’s next?

Working with Environment Variables

What is an API?

`requests` Module

Common HTTP Methods

Example: GET Request

Example: POST Request

Useful Response Attributes

Common Status Codes

Let’s get real weather data using a free weather API:

Understanding the response

Extract what you need

How it works

Practice & Exercises

What’s next?