input: Write a function to generate a simple HTML form with a submit button that sends information to a Python program. The form should use the POST method and submit to a file named "action.py".
  
  assert generate_form()==('<form action="action.py" method="post">\n    <input type="submit" value="Submit">\n</form>')
  assert generate_form()=='<form action="action.py" method="post">\n    <input type="submit" value="Submit">\n</form>'
  assert generate_form()!='<form action="action.py" method="get">\n    <input type="submit" value="Submit">\n</form>'
  assert generate_form()!='<form action="action.py" method="post">\n</form>'
  assert generate_form()!='<form action="another_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>'