How to do it...

1. Import Selenium, start a browser, and load the form page. A page will open reflecting the operations:

>>> from selenium import webdriver
>>> browser = webdriver.Chrome()
>>> browser.get('https://httpbin.org/forms/post')

2. Add a value in the Customer name field. Remember that it is called custname:

>>> custname = browser.find_element_by_name("custname")
>>> custname.clear()
>>> custname.send_keys("Sean O'Connell")

The form will update:

3. Select the pizza size as medium:

>>> for size_element in browser.find_elements_by_name("size"):
...     if size_element.get_attribute('value') == 'medium':
...         size_element.click()
...
>>>

This will change the pizza size ratio box.

4. Add bacon and cheese:

>>> for topping in browser.find_elements_by_name('topping'):
...     if topping.get_attribute('value') in ['bacon', 'cheese']:
...         topping.click()
...
>>>

Finally, the checkboxes will appear as marked:

5. Submit the form. The page will submit and the result will be displayed:

>>> browser.find_element_by_tag_name('form').submit()

The form will be submitted and the result from the server will be displayed:

6. Close the browser:

>>> browser.quit()