TypeError: object of type 'NoneType' has no len() - what do it mean?

[leviathan54]

note: i have another forum topic going with the same project. I've whited out a few lines to I can continue to practice until i resolve the other forum issue.
https://python-forum.io/Thread-Permissio...nied-error
In the mean time i have another issue which i'm raising here. Please be patient, i'm trying to learn and have a long long way to go with my development.

I have my code able to successfully look at a spreadsheet with a mix of working and not working username and passwords. The code will successfully add the username and password for the 4 different test cases but then gives the error message

TypeError: object of type 'NoneType' has no len

C:\Python37\python.exe C:/Users/David/PycharmProjects/POM/DataDrivenTestCase.py
test is passed
test failed
test failed
test failed
Traceback (most recent call last):
  File "C:/Users/David/PycharmProjects/POM/DataDrivenTestCase.py", line 24, in <module>
    driver.find_element_by_name("userName").send_keys(username)
  File "C:\Python37\lib\site-packages\selenium\webdriver\remote\webelement.py", line 478, in send_keys
    {'text': "".join(keys_to_typing(value)),
  File "C:\Python37\lib\site-packages\selenium\webdriver\common\utils.py", line 150, in keys_to_typing
    for i in range(len(val)):
TypeError: object of type 'NoneType' has no len()

I'm guessing this is because of the loop I have? to it looks at the first 5 rows in my spreadsheet which have conditions and then hits the 6th row which is blank? Would my assumption be right?

If so what do i need to change?

I'm assuming i need to add some other condition to the following line

for r in range(2, rows):
    username = XLUtils.readData(path, "Sheet1", r, 1)
    password = XLUtils.readData(path, "Sheet1", r, 2)

Here is the code from the module of interest

from selenium import webdriver
import unittest
import XLUtils
 
profile_path = 'C:/FireFoxProfile'
profile = webdriver.FirefoxProfile(profile_path)
driver = webdriver.Firefox(firefox_profile=profile_path)
driver.implicitly_wait(5)
driver.get('http://www.demoaut.com/')
driver.maximize_window()
 
[b]path = "C://FireFoxProfile/login1.xlsx"[/b]
 
rows = XLUtils.getRowCount(path, 'Sheet1')
 
for r in range(2, rows):
    username = XLUtils.readData(path, "Sheet1", r, 1)
    password = XLUtils.readData(path, "Sheet1", r, 2)
 
    driver.find_element_by_name("userName").send_keys(username)
    driver.find_element_by_name("password").send_keys(password)
 
    driver.find_element_by_name("login").click()
 
    if driver.title == "Find a Flight: Mercury Tours:":
        print("test is passed")
        XLUtils.writeData(path, "Sheet1", r, 3, "test passed")
    else:
        print("test failed")
        XLUtils.writeData(path, "Sheet1", r, 3, "test failed")
 
    driver.find_element_by_link_text("Home").click()
 
    @classmethod
    def tearDownClass(cls):
        cls.driver.quit()
 
if __name__ == '__main__':
    unittest.main(verbosity=2)