input: Write a function to create a web application in Python using Flask that takes user input and generates an HTML page with the input. If the input is received, show the input in the HTML page, else display a default message. 
  
  from flask import Flask, render_template, request
  
  app = Flask(__name__)
  
  @app.route('/', methods=['GET', 'POST'])
  def home():
      if request.method == 'POST':
          input_text = request.form.get('input_text')
          return render_template('result.html', input_text=input_text)
      return render_template('index.html')
  
  if __name__ == '__main__':
      app.run(debug=True)
  
  // result.html file
  <html>
   <body>
    <h1>Your Input: </h1>
    <p>{{input_text}}</p>
   </body>
  </html>
  
  assert home() == render_template('index.html')
  assert home(input_text="Hello World") == render_template('result.html', input_text="Hello World")
output: 
  def home():
      if request.method == 'POST':
          input_text = request.form.get('input_text')
          return render_template('result.html', input_text=input_text)
      return render_template('index.html')
  