app.py

from flask import Flask, render_template, request, json
app = Flask(__name__)

@app.route("/")
def main():
        return render_template('index.html')

@app.route('/showSignup')
def showSignup():
        return render_template('signup.html')

@app.route('/signUp', methods=['POST'])
def signUp():
        # read the posted values from the UI 
        _name = request.form['inputName']
        _email = request.form['inputEmail']
        _password = request.form['inputPassword']

        # validate the received files
        if _name and _email and _password:
                return json.dumps({'html':'<span>All fields good !!</span>'})
        else:
                return json.dumps({'html':'<span>Enter the required fields</span>'})

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