input: Write a function to generate an HTML form with a submit button that sends information to a Python program. The function should return the HTML form as a string.
  assert generate_form()=='\<form action="action.py" method="post">\n    \<input type="submit" value="Submit">\n\</form>'
output: def generate_form():
      return '<form action="action.py" method="post">\n    <input type="submit" value="Submit">\n</form>'