Since Python 3.6, string interpolation has been available in the form of f-strings. These allow you to add variables directly into a string making it clearer to understand when reviewing code. i.e.
output = f"Test failed. Expected {expected_response}, but received {actual_response}"
Currently Test Complete highlights the entire string, including the variables as the same colour. It would be nicer if there was different highlighting on the variable colours to the string so that they stand out more.