# 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()

# 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.

import flask
# A simple Flask App which takes
# a user's name as input and responds
# with "Hello {name}!"
app = flask.Flask(__name__)
@app.route('/', methods=['GET', 'POST'])
def index(): message = '' if flask.request.method == 'POST': message = 'Hello ' + flask.request.form['name-input'] + '!' return flask.render_template('index.html', message=message)
if __name__ == '__main__': app.run()

from flask import Flask
app = Flask(__name__)
@app.route("/")
def hello_world(): return "<p>Hello, World!</p>"

#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)

# save this as app.py
from flask import Flask, escape, request
app = Flask(__name__)
@app.route('/')
def hello(): name = request.args.get("name", "World") return f'Hello, {escape(name)}!' # twitter : @MasudSha_ # @MasudShah

>>> from yourapp import create_app
>>> app = create_app()
>>> app.app_context().push()