server.py

# coding: utf-8
from flask import Flask, request, render_template
app = Flask(__name__)
temperature = float("NaN")
pressure = float("NaN")
humidity = float("NaN")

@app.route("/",methods=['POST'])
def info():
    global temperature, pressure, humidity
    temperature = float(request.form['temp'])
    pressure = float(request.form['pres'])
    humidity = float(request.form['hum'])
    return render_template('index.html',
                           t=temperature,
                           h=humidity,
                           p=pressure)

@app.route("/", methods=["GET"])
def view():
    return render_template('index.html',
                           t=temperature,
                           h=humidity,
                           p=pressure)

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