app.py

# This python script creates an API by using 
# SQLite3 as its backend database

import flask
from flask import request, jsonify

import sqlite3
from sqlite3 import Error

app = flask.Flask(__name__)
app.config['DEBUG'] = True

# This function returns the output of a query 
# in the form of a dictionary
def dict_factory(cursor, row):
    d = {}
    for idx, col in enumerate(cursor.description):
        d[col[0]] = row[idx]
    return d

# This function initializes the Database
def initialize_db():
    connect = sqlite3.connect('mock_ahms.db')
    return connect

# This function shows the home page of the API
@app.route('/', methods=['GET'])
def home():
    return '''
    <h1>Welcome to the AHMS API Home Page</h1>
    '''

# This function fetches all the data present in the database
@app.route('/v1/resources/ahms/all', methods=['GET'])
def all_fruits():
    connect = initialize_db()
    connect.row_factory = dict_factory
    cursor = connect.cursor()
    data = cursor.execute('''
    SELECT * FROM ahms;
    ''').fetchall()

    return jsonify(data)

# This function fetches data based on the filter provided by the user
@app.route('/v1/resources/ahms', methods=['GET'])
def filterd_fruits():
    query_parameters = request.args

    student_id = query_parameters.get('student_id')
    has_stayback = query_parameters.get('has_stayback')

    query = 'SELECT * FROM ahms WHERE'
    filters = []

    if student_id:
        query = query + ' student_id=? AND'
        filters.append(student_id)
    if has_stayback:
        query = query + ' has_stayback=? AND'
        filters.append(has_stayback)

    if not (student_id or has_stayback):
        page_not_found()
    
    # This removes everything till the fourth last character in the 
    # final query
    query = query[:-4] + ';'

    conn = initialize_db()
    conn.row_factory = dict_factory
    cursor = conn.cursor()

    data = cursor.execute(query, filters).fetchall()
    return jsonify(data)

# This function shows a error page if the API is not called correctly
@app.errorhandler(404)
def page_not_found():
    return '''
    <p>Ah oh, page not found :(</p>
    '''

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