flask render on this route code example

Example 1: python render_template

from flask import Flask
from flask import render_template
app = Flask(__name__)

@app.route('/')
def index():
   return render_template("index.html") #if you want to render a .html file,
                        # import render_template from flask and use
                        #render_template("index.html") here.

if __name__ == '__main__':
    app.debug = True
    app.run() #go to http://127.0.0.1:5000/ to view the page.

Example 2: flask site route

from flask import render_template

@app.route('/hello/')
@app.route('/hello/<name>')
def hello(name=None):
    return render_template('hello.html', name=name)
  
---------------------------------------------------
<!doctype html>
<title>Hello from Flask</title>
{% if name %}
  <h1>Hello {{ name }}!</h1>
{% else %}
  <h1>Hello, World!</h1>
{% endif %}