Simple CRUD API

March 15, 2026

Question

Build a simple Flask REST API for managing student records. You can consider this as the starter data :

students = [
   {"id": 1, "name": "Pradyumna", "age": 24, "course": "Computer Science", "city": "Austin"},
   {"id": 2, "name": "Rahul", "age": 22, "course": "Data Science", "city": "Dallas"},
   {"id": 3, "name": "Ananya", "age": 21, "course": "Electronics", "city": "Houston"},
   {"id": 4, "name": "Kiran", "age": 23, "course": "Computer Science", "city": "Austin"},
   {"id": 5, "name": "Sachin", "age": 20, "course": "Mechanical", "city": "Seattle"}
]

The tasks include :

GET /students : Get all students
GET /students/:id : Get a student by id
POST /students : Create a new student
PUT /students/:id : Update a student by id
DELETE /students/:id : Delete a student by id
Search /students?name=:name : Search students by course and city

Solution

So given the in memory data, we are building a simple CRUD API for managing student records.

The APIs would be GET, POST, PUT, DELETE. Lets start with the GET API.

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

Now lets GET a student by id.

# api endpoint : /students/:student_id
@app.route("/students/<int:student_id>", methods = ['GET'])
def get_students_by_id(student_id: int): 
  for student in students: 
    if student['id'] == student_id: 
      return jsonify(student)
  return jsonify({"error": "Student not found"}), 404

Now lets POST a new student.

# api endpoint : /students
@app.route("/students", methods = ['POST'])
def create_student(): 
  data = request.json
  new_Student = {
    "id": len(students) + 1,
    "name" : data['name'],
    "age" : data["age"], 
    "course" : data["course"],
    "city" : data["city"]
  }
  students.append(new_Student)
  return jsonify(new_Student), 201

Now lets PUT an existing student.

# api endpoint : /students/:student_id
@app.route("/students/<int:student_id>", methods = ['PUT'])
def update_student(student_id: int): 
  data = request.json
  for student in students: 
    if student['id'] == student_id: 
      student['name'] = data['name']
      student['age'] = data['age']
      student['course'] = data['course']
      student['city'] = data['city']
      return jsonify(student), 200
  return jsonify({"error": "Student not found"}), 404

Now lets DELETE a student.

# api endpoint : /students/:student_id
@app.route("/students/<int:student_id>", methods = ['DELETE'])
def delete_student(student_id: int): 
  for student in students: 
    if student['id'] == student_id: 
      students.remove(student)
      return jsonify({"message": "Student deleted successfully"}), 200
  return jsonify({"error": "Student not found"}), 404

Lets search students by course and city.

# api endpoint : /students?course=:course&city=:city
@app.route("/students", methods = ['GET'])
def search_students() : 
  course = request.args.get('course')
  city = request.args.get('city')
  results = []
  for student in students : 
    if student['course'] == course and student['city'] == city : 
      results.append(student)
  return jsonify(results), 200

Follow up questions

Now introduce the concept of pagination to the API.
Consider now the data grows, and we store it in a database.

THis would be the solution to the pagination problem.

# api endpoint : /students?page=:page&limit=:limit
@app.route("/students", methods = ['GET'])
def get_students_paginated() : 
  page = request.args.get('page', 1, type = int)
  limit = request.args.get('limit', 10, type = int)
  start = (page - 1) * limit
  end = start + limit
  return jsonify(students[start:end]), 200

Now if i say that the data is stored in a database, and we need to fetch the data from the database, then i would do it this way..

@app.route("/students", methods = ['GET'])
def get_students():