Deploying a Number Classification API on AWS Lambda + API Gateway using Zappa

Overview

This project is a Flask-based API that provides interesting mathematical properties of a given number. It determines whether a number is prime, perfect, or an Armstrong number, and also provides its digit sum and a fun fact.

Zappa makes it super easy to build and deploy serverless, event-driven python applications(including, but not limited to, WSGI web apps) on AWS Lambda + API Gateway. Find more info about Zappa here.

Note that you would need an AWS CLI user setup with necessary permissions to lambda and api gateway.

Features

• Determines if a number is prime, perfect, or an Armstrong number.

• Computes the sum of digits.

• Returns a fun fact about the number.

• Supports CORS for cross-origin access.

• Returns responses in JSON format.

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Setup Necessary Tools and Dependencies.

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First of all, Ensure you have python installed. You can go through the python documentation to assist you.

Install Flask and Zappa.

pip install flask flask-cors zappa

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Setup your API on app.py in your local environment

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from flask import Flask, request, jsonify
from flask_cors import CORS
import requests
import math

app = Flask(__name__)
CORS(app)

def is_prime(num):
    if num <= 1 or num % 1 != 0:
        return False
    num = int(num)
    for i in range(2, int(math.sqrt(num)) + 1):
        if num % i == 0:
            return False
    return True

def is_armstrong(num):
    if num % 1 != 0:  # Only whole numbers can be Armstrong numbers
        return False
    num = abs(int(num))
    digits = [int(digit) for digit in str(num)]
    power = len(digits)
    return sum(digit ** power for digit in digits) == num

def get_fun_fact(num):
    url = f"http://numbersapi.com/{num}/math"
    response = requests.get(url)
    return response.text if response.status_code == 200 else "No fun fact found"

@app.route('/api/classify-number', methods=['GET'])
def classify_number():
    number = request.args.get('number')

    try:
        number = float(number)
    except (ValueError, TypeError):
        return jsonify({"number": number, "error": "true"}), 400

    armstrong = is_armstrong(number)
    prime = is_prime(number)
    even = number % 2 == 0
    digit_sum = sum(map(int, str(abs(int(number)))))
    fun_fact = get_fun_fact(int(number))

    properties = []
    if armstrong:
        properties.append("armstrong")
    properties.append("even" if even else "odd")

    return jsonify({
        "number": number,
        "is_prime": prime,
        "is_perfect": False,  # No perfect number check required
        "properties": properties,
        "digit_sum": digit_sum,
        "fun_fact": fun_fact
    })

if __name__ == "__main__":
    app.run()

Test your API Locally

http://127.0.0.1:5000/api/classify-number?number=-100.5


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Deploy API with Zappa on AWS Lambda using API Gateway

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Initialize Zappa

zappa init

Follow the prompts to configure deployment settings.

Deploy your Flask app to AWS Lambda using the code below:

zappa deploy dev

This would take a while. After deployment, a link will be shared to access your API.

If you make update to your function, you can always update lambda using the code below

zappa update dev

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Zappa will automatically set up a regularly occurring execution of your application to keep the Lambda function warm. This helps optimize speed and produces fast response time.

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You can confirm the creation of the AWS Lambda function and API Gateway on your AWS Console and also make changes there.