The description stated length less than 3 should return false, but this is not implemented. Non letters should not be considered

python tests are wrong, both test cases and sample tests:

• don't use test.expect
• assert_equals will do the them without inconsistencies between the message and the expected value (see sample tests)
• in the message, display the input string too. Without it, the message is useless
• no random tests
• example tests are lacking in the test cases
• The function should also return false if the string has a length of less than 3 letters or fewer than 3 alphabetical characters. => this behavior isn't tested in the test cases and moreover, in the sample tests where they are tested, the wrong answer is expected!

The sample test for test "aa" and "bob" expect false when they are in fact plaindromes.

It's similar to many others and a duplicate too, you will find a list at: https://www.codewars.com/kata/search/?q=palindrom