Python wsgi example: problem with javascript

[snippsat]

As a example can change zoom value on map.
So when start now it's on zoom 6 and not zoom 2.

from flask import Flask,render_template,request

app = Flask(__name__)
@app.route('/')
def open_layer():
    zoom = {'val': '6'}   
    return render_template("index.html", zoom=zoom)

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

In index.html:

zoom: {{ zoom['val'] }}