This function adds an element to a list inside a dict of lists. Rewrite it to use a try-except statement which handles a possible KeyError if the list with the name provided doesn’t exist in the dictionary yet, instead of checking beforehand whether it does. Include else and finally clauses in your try-except block:

thedict = [] # You can use existing dict as well
# function takes a dict, a list name and the element
def add_to_list_in_dict(thedict, listname, element):
    if listname in thedict:
        l = thedict[listname]
        print("%s already has %d elements." % (listname, len(l)))
    else:
        thedict[listname] = []
        print("Created %s." % listname)
        thedict[listname].append(element)
        print("Added %s to %s." % (element, listname))
thedict[listname].append(element)
print("Added %s to %s." % (element, listname))