To check if a list is empty, the following is preferred in Python:

    if not feedparser.get_presentations_list():
        # list is empty, do something 

It's a bit unusual coming from different languages, but this is generally the best way in Python.

It's also recommended in the styleguides we use [[1]](http://www.python.org/dev/peps/pep-0008/#programming-recommendations) [[2]](http://google-styleguide.googlecode.com/svn/trunk/pyguide.html?showone=True/False_evaluations#True/False_evaluations)

> For sequences, (strings, lists, tuples), use the fact that empty sequences are false.

>     Yes: if not seq:
         if seq:

>     No: if len(seq)
        if not len(seq)