Dear anne123,

After you "attempted", if you pass all tests, normally the button "Attempt" becomes "Submit" and you have to click on it.

Indeed! Thank you very much for your answer!!!
What is happening exactly when you launch the tests through "Run Examples" or "Attempt"? I mean behind the button... How these "sections" are organized? The following text is written in the exercise but I don't really get it. Could you explain a bit?

TODO: Replace examples and use TDD development by writing your own tests

These are some of the methods available:

test.expect(boolean, [optional] message)

test.assert_equals(actual, expected, [optional] message)

test.assert_not_equals(actual, expected, [optional] message)

You can use Test.describe and Test.it to write BDD style test groupings

If I write:

def whatCentury(year):
return True (=> with the indentation of course)

Or even:

def whatCentury(year):
print(year) (=> with the indentation of course)

In Python 3.4 the output is "error" without explanation... Do you know why?

Very clever! I like it :-)
Bravo!