Quickly implement REST API in Python

Since I learned about API in the study session, I implemented a simple REST API in Python. How to install Python is explained elsewhere, so I will omit it.

environment

• CentOS 7.0
• Python 3.5.1
• SQLite3 3.9.2

Module installation

With Flask, a web application framework Install Peewee of ORM.

$ pip install flask
$ pip install peewee

Data import

Import the following data into the database.

user.tsv

#userId     userCompany  	userDiscountRate
Us0ymuik Dense Forest Compliance Printing 46
Us77qmr2 West Japan Dense Forest Entertainment 49
Usdj7ej1 jungle solution 18
Usjx15uh Yokohama Huge Hard Software 7
Usqd7wpe Shinkin bank 1
Uswvrn3s Golden Mobile Solution 7
Us3h2d0a Benza Social Gaming Solution 26
Usa4c2hm Virtualware Social Gaming Industry 7
.
.
.

Connect to the database with Peewee and register the data.

import.py

# -*- coding: utf-8 -*-
import peewee

#Specify database
db = peewee.SqliteDatabase("data.db")

#Define user model
class User(peewee.Model):
    userId = peewee.TextField()
    userCompany = peewee.TextField()
    userDiscountRate = peewee.IntegerField()

    class Meta:
        database = db

#User table creation
User.create_table()

#Read the tsv file line by line, divide it by tabs, and register each in the database
for line in open("user.tsv", "r"):
    (userId, userCompany, userDiscountRate) = tuple(line[:-1].split("\t"))
    if userDiscountRate.isdigit(): #Supports comments on the first line.
        User.create(userId = userId,
                    userCompany = userCompany,
                    userDiscountRate = int(userDiscountRate))

API implementation

API specifications

Function: Get customer information

path: getUser /: userId

method: GET

api.py

# -*- coding: utf-8 -*-
from flask import Flask, jsonify, abort, make_response
import peewee
# import json

db = peewee.SqliteDatabase("data.db")

class User(peewee.Model):
    userId = peewee.TextField()
    userCompany = peewee.TextField()
    userDiscountRate = peewee.IntegerField()

    class Meta:
        database = db

api = Flask(__name__)

@api.route('/getUser/<string:userId>', methods=['GET'])
def get_user(userId):
    try:
        user = User.get(User.userId == userId)
    except User.DoesNotExist:
        abort(404)

    result = {
        "result":True,
        "data":{
            "userId":user.userId,
            "userCompany":user.userCompany,
            "userDiscountRate":user.userDiscountRate
            }
        }

    return make_response(jsonify(result))
    #If you don't want to use Unicode ↓
    # return make_response(json.dumps(result, ensure_ascii=False))

@api.errorhandler(404)
def not_found(error):
    return make_response(jsonify({'error': 'Not found'}), 404)

if __name__ == '__main__':
    api.run(host='0.0.0.0', port=3000)

Verification

$ curl -i http://0.0.0.0:3000/getUser/Usdj7ej1
HTTP/1.0 200 OK
Content-Type: text/html; charset=utf-8
Content-Length: 118
Server: Werkzeug/0.11.10 Python/3.5.1
Date: Fri, 27 May 2016 06:29:57 GMT

{"data": {"userCompany": "Dense forest solution", "userDiscountRate": 18, "userId": "Usdj7ej1"}, "result": true}%