Activity 34: Basic Crud Python FLask API (SIA2)

1. Create a Project Folder:

   • First, create a new folder where you want to store your project files.

   • Open a terminal or command prompt and navigate to that folder.

Commands:

    mkdir flask_api_project
    cd flask_api_project

2. Create the Virtual Environment:

   • In your project folder, create a virtual environment to keep your dependencies isolated.

Commands:

    python -m venv myenv

3. Activate the Virtual Environment:

   • On Windows:

       .\myenv\Scripts\activate
     

After activating, you should see (myenv) in the command line, indicating the virtual environment is active.

4. Install Flask:

   • Once the virtual environment is activated, install Flask using pip.

Command:

    pip install Flask

5. Create the app.py file:

   • In your project folder, create a new file named app.py. This file will contain the Flask API code.

6. Write the Flask API Code:

   • Open app.py in a text editor and add the following code:

    # Import necessary libraries
    from flask import Flask, jsonify, request

    # Initialize the Flask application
    app = Flask(__name__)

    # Sample data: list of students
    students = [
        {"name": "Juan Carlos", "section": "BSIT-4B", "id": 1, "email": "juan@gmail.com", "age": 22},
        {"name": "Jose Rizal", "section": "BSIT-2A", "id": 2, "email": "jose@gmail.com", "age": 21}
        # Add more students if needed
    ]

    # GET all students
    @app.route('/students', methods=['GET'])
    def get_students():
        return jsonify(students)

    # GET a specific student by ID
    @app.route('/students/<int:student_id>', methods=['GET'])
    def get_student(student_id):
        student = next((student for student in students if student["id"] == student_id), None)
        if student:
            return jsonify(student)
        else:
            return jsonify({"message": "Student not found"}), 404

    # POST: Add a new student
    @app.route('/students', methods=['POST'])
    def add_student():
        new_student = request.get_json()
        new_student['id'] = max(student['id'] for student in students) + 1  # Generate new ID
        students.append(new_student)
        return jsonify(new_student), 201

    # PUT: Update an existing student by ID
    @app.route('/students/<int:student_id>', methods=['PUT'])
    def update_student(student_id):
        student = next((student for student in students if student["id"] == student_id), None)
        if student:
            data = request.get_json()
            student.update(data)
            return jsonify(student)
        else:
            return jsonify({"message": "Student not found"}), 404

    # DELETE: Remove a student by ID
    @app.route('/students/<int:student_id>', methods=['DELETE'])
    def delete_student(student_id):
        student = next((student for student in students if student["id"] == student_id), None)
        if student:
            students.remove(student)
            return jsonify({"message": "Student deleted"})
        else:
            return jsonify({"message": "Student not found"}), 404

    # Run the application
    if __name__ == '__main__':
        app.run(debug=True)

7. Run the Server:

   • In the terminal, ensure you are still in the same directory as app.py.

   • Start the Flask server by running:

Command:

    python app.py

8. Test the API:

   • Open your POSTMAN

     • GET /students: Lists all students.

       

     • GET /students/<id>: Retrieves a specific student by ID.

       

     • POST /students: Adds a new student (requires JSON data).

       

     • PUT /students/<id>: Updates an existing student.

       

     • DELETE /students/<id>: Deletes a student.