REST API with Flask Project code in Python

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REST API with Flask in Python

About the project: This is a simple REST API project using the Flask framework, all contained within a single, self-contained Python file.

This project will demonstrate the fundamental principles of a RESTful API by creating a simple endpoint to manage a collection of books.

You can perform common actions like retrieving all books, getting a specific book, adding a new book, and updating or deleting an existing one.

Instructions

1. Install Flask: This project requires the Flask library. You'll need to install it first if you don't have it already.

   
     pip install Flask
     

2. Save the Code: Save the code below as a file named rest_api.py.
3. Run the App: Open your terminal or command prompt, navigate to the directory where you saved the file, and run the script:

   
     python rest_api.py
     

4. Access the API: The API will be running at http://127.0.0.1:5000. You can use tools like curl or a browser extension like Postman to interact with the endpoints.

This project provides a solid foundation for building more complex APIs.
If you'd like to extend this, you could explore adding a real database, incorporating user authentication, or even adding a front-end to interact with it.

Project Level: Intermediate

You can directly copy the below snippet code with the help of green copy button, paste it and run it in any Python editor you have.

Steps: Follow these steps

Step 1: Copy below code using green 'copy' button.

Step 2: Paste the code on your chosen editor.

Step 3: Save the code with filename and .py extention.

Step 4: Run (Press F5 if using python IDLE).

# rest_api.py

from flask import Flask, jsonify, request

# Initialize the Flask application
app = Flask(__name__)

# A simple list of dictionaries to act as our in-memory database
# In a real-world application, this would be a database like PostgreSQL or MongoDB
books = [
    {
        'id': 1,
        'title': 'The Lord of the Rings',
        'author': 'J.R.R. Tolkien',
        'published': 1954
    },
    {
        'id': 2,
        'title': 'Dune',
        'author': 'Frank Herbert',
        'published': 1965
    },
    {
        'id': 3,
        'title': 'Foundation',
        'author': 'Isaac Asimov',
        'published': 1951
    }
]

# --- API Endpoints ---

@app.route('/books', methods=['GET'])
def get_all_books():
    """
    Handles GET requests to retrieve the list of all books.
    Returns:
        A JSON object containing the list of books.
    """
    return jsonify({'books': books})


@app.route('/books/', methods=['GET'])
def get_book_by_id(book_id):
    """
    Handles GET requests to retrieve a single book by its ID.
    Args:
        book_id (int): The ID of the book to retrieve.
    Returns:
        A JSON object for the book if found, otherwise an error message.
    """
    book = next((book for book in books if book['id'] == book_id), None)
    if book:
        return jsonify({'book': book})
    else:
        # Return a 404 Not Found error if the book is not in the list
        return jsonify({'error': 'Book not found'}), 404


@app.route('/books', methods=['POST'])
def add_new_book():
    """
    Handles POST requests to add a new book to the list.
    The request must contain a JSON body with 'title' and 'author'.
    Returns:
        A JSON object for the newly created book.
    """
    # Check if the request body is valid JSON
    if not request.json or 'title' not in request.json or 'author' not in request.json:
        return jsonify({'error': 'Invalid request format. Must contain title and author.'}), 400

    new_book = {
        'id': books[-1]['id'] + 1 if books else 1,
        'title': request.json['title'],
        'author': request.json['author'],
        'published': request.json.get('published') # 'published' is optional
    }
    books.append(new_book)
    # Return a 201 Created status code
    return jsonify({'book': new_book}), 201


@app.route('/books/', methods=['PUT'])
def update_book(book_id):
    """
    Handles PUT requests to update an existing book by its ID.
    The request must contain a JSON body with the fields to update.
    Returns:
        A JSON object for the updated book.
    """
    book = next((book for book in books if book['id'] == book_id), None)
    if not book:
        return jsonify({'error': 'Book not found'}), 404

    # Update the book with any fields provided in the request
    if 'title' in request.json:
        book['title'] = request.json['title']
    if 'author' in request.json:
        book['author'] = request.json['author']
    if 'published' in request.json:
        book['published'] = request.json['published']

    return jsonify({'book': book})


@app.route('/books/', methods=['DELETE'])
def delete_book(book_id):
    """
    Handles DELETE requests to remove a book from the list by its ID.
    Returns:
        A confirmation message.
    """
    book = next((book for book in books if book['id'] == book_id), None)
    if not book:
        return jsonify({'error': 'Book not found'}), 404

    books.remove(book)
    return jsonify({'message': 'Book deleted successfully'})


# Run the application
if __name__ == '__main__':
    # Setting debug=True reloads the server automatically on code changes
    # It should be set to False in a production environment
    app.run(debug=True, host='0.0.0.0', port=5000)

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