Count number of empty array occurrences within a 2D array

Question

I'm looking to count the number of occurrences of an empty array within a 2D array in the most efficient manner. For example :

array = [[a,b],[a,b,c],[a],[],[],[],[]]

The answer I would like to get should be 4 .

How do we get around doing that without using a lengthy for loop process? It shouldn't also use Numpy, just plain simple Python. I tried .count, but I doesn't quite work with empty arrays.

Answer 1

Here is my short solution using the list.count() method:

array = [[a,b],[a,b,c],[a],[],[],[],[]]

print(array.count([])) # 4

Answer 2

array = [[a,b],[a,b,c],[a],[],[],[],[]]
answer = len([a for a in array if not a])

>>> answer
4

Answer 3

array = [[1,2],[1,2,3],[1],[],[],[],[]]

print(sum(1 for arr in array if not arr)) # 4

Answer 4

I would use the array.count([]) method but just introducing an option that has not been displayed

print(len(list(filter(lambda x: x == [], array))))
# 4