flask-node.md

Communication between Express & Flask

Express.js

• Create a route in Express
• Load the request library
• Call the Flask API using request
• The response from Flask will be in body
• Send the Flask response back to the original caller with res.send(body)

var request = require('request');
app.get('/users', function(req, res){
  request('http://url-to-your-flask-app/data/3', function(err, resp, body){
    res.send(body);
  });
});

Flask

• Install Flask pip install flask
• Install Postgres library pip install psycopg2 or conda install psycopg2
• Create a main.py file

from flask import Flask, request, json, jsonify
app = Flask(__name__)

import sys
sys.path.append('.')
from user import User

@app.route("/users/<id>", methods=['GET'])
def money(id):
    rows = User.money(id)
    return jsonify(rows=rows)

if __name__ == "__main__":
    app.run(debug=True, host='0.0.0.0')

• Create user.py, will be used to talk to the Postgres database

import psycopg2

class User:
    def money(id):
        conn = psycopg2.connect("dbname=ge_sales_dev user=postgres password=chyld host=127.0.0.1")
        cur = conn.cursor()
        cur.execute('SELECT * FROM "Sales" where user_id = ' + id + ';')
        data = cur.fetchall()
        cur.close()
        conn.close()
        return data