python basic flask app code example

Example 1: simple flask app

# Extremely simple flask application, will display 'Hello World!' on the screen when you run it
# Access it by running it, then going to whatever port its running on (It'll say which port it's running on).
from flask import Flask
app = Flask(__name__)

@app.route('/')
def hello_world():
    return 'Hello, World!'

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

Example 2: flask how to run app

$ export FLASK_APP=hello.py
$ python -m flask run
 * Running on http://127.0.0.1:5000/

Example 3: post request in python flaks

import json
import requests

api_url = 'http://localhost:5000/create-row-in-gs'
create_row_data = {'id': '1235','name':'Joel','created_on':'27/01/2018','modified_on':'27/01/2018','desc':'This is Joel!!'}
print(create_row_data)
r = requests.post(url=api_url, json=create_row_data)
print(r.status_code, r.reason, r.text)
Server:

from flask import Flask,jsonify,request,make_response,url_for,redirect
import requests, json

app = Flask(__name__)

url = 'https://hooks.zapier.com/hooks/catch/xxxxx/yyyyy/'

@app.route('/create-row-in-gs', methods=['GET','POST'])
def create_row_in_gs():
    if request.method == 'GET':
        return make_response('failure')
    if request.method == 'POST':
        t_id = request.json['id']
        t_name = request.json['name']
        created_on = request.json['created_on']
        modified_on = request.json['modified_on']
        desc = request.json['desc']

        create_row_data = {'id': str(t_id),'name':str(t_name),'created-on':str(created_on),'modified-on':str(modified_on),'desc':str(desc)}

        response = requests.post(
            url, data=json.dumps(create_row_data),
            headers={'Content-Type': 'application/json'}
        )
        return response.content

if __name__ == '__main__':
    app.run(host='localhost',debug=False, use_reloader=True)

Example 4: python basic flask app

# Imports necessary libraries
from flask import Flask 
# Define the app
app = Flask(__name__)

# Get a welcoming message once you start the server.
@app.route('/')
def home():
    return 'Home sweet home!'

# If the file is run directly,start the app.
if __name__ == '__main__':
    app.run(Debug=True)

# To execute, run the file. Then go to 127.0.0.1:5000 in your browser and look at a welcoming message.

Example 5: basic flask app python

#Import Flask, if not then install and import.

import os
try:
  from flask import *
except:
  os.system("pip3 install flask")
  from flask import *

app = Flask(__name__)

@app.route("/")
def index():
  return "<h1>Hello World</h1>"

if __name__ == "__main__":
  app.run(host="0.0.0.0", port=8080, debug=False)