flask application sample with mysql connection and query inside

anfield-app.py

from flask import Flask, jsonify
import os
import pymysql.cursors

app = Flask(__name__)

MYSQL_HOST = os.getenv('ANFIELD_HOST')
MYSQL_USER = os.getenv('ANFIELD_USER')
MYSQL_PASS = os.getenv('ANFIELD_PASS')
MYSQL_DBN = os.getenv('ANFIELD_DBN')
MYSQL_PORT = os.getenv('ANFIELD_PORT', '3306')

def player_list():
    connection = pymysql.connect(
                    host=MYSQL_HOST,
                    user=MYSQL_USER,
                    password=MYSQL_PASS,
                    db=MYSQL_DBN,
                    port=int(MYSQL_PORT),
                    cursorclass=pymysql.cursors.DictCursor
            )
    try:
        with connection.cursor() as cursor:
            query_str = "SELECT * FROM players"
            cursor.execute(query_str)
            result = cursor.fetchall()
    finally:
        connection.close()
    return result

@app.route("/")
def index():
    return "Hello, this is index"

@app.route("/players")
def players():
    pl = player_list()
    return jsonify(pl)

if __name__ == '__main__':
    app.run(host="0.0.0.0", port="5050")