how to run flask code example

Example 1: debug flask powershel

$env:FLASK_ENV = "development"

Example 2: 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 3: flask how to run app

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

Example 4: install flask

pip install -U Flask

Example 5: flask.pocoo.org quickstart

from flask import Flask
app = Flask(__name__)

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

Example 6: default flask app

from flask import Flask
app = Flask(__name__)

@app.route('/')
def index():
    return 'Flask'