[SOLVED] Python: How to check if a nested list is essentially empty?

Python: How to check if a nested list is essentially empty?

Is there a Pythonic way to check if a list (a nested list with elements & lists) is essentially empty? What I mean by empty here is that the list might have elements, but those are also empty lists.

The Pythonic way to check an empty list works only on a flat list:

alist = []
if not alist:
    print("Empty list!")

For example, all the following lists should be positive for emptiness:

alist = []
blist = [alist]               # [[]]
clist = [alist, alist, alist] # [[], [], []]
dlist = [blist]               # [[[]]]

Solution

I have combined the use of isinstance() by Ants Aasma and all(map()) by Stephan202, to form the following solution. all([]) returns True and the function relies on this behaviour. I think it has the best of both and is better since it does not rely on the TypeError exception.

def isListEmpty(inList):
    if isinstance(inList, list): # Is a list
        return all( map(isListEmpty, inList) )
    return False # Not a list