QuerySelect and QuerySelectList

As per PEP257, docstrings should be in the imperative mode.

> The docstring is a phrase ending in a period. It prescribes the function or method's effect as a command ("Do this", "Return that"), not as a description; e.g. don't write "Returns the pathname ...". 

https://www.python.org/dev/peps/pep-0257/#one-line-docstrings