How to count elements in nested lists

Question

How do I count the number of elements in a nested list?

I want to transform:

myList = [[0],[1,4,5,8],[5],[2,3,9],[7,7]]

into:

myList = [1, 4, 1, 3, 2]

Answer 1

Python gives you the map function which allows you to apply a function to each element in a list. You could simply write:

result = list(map(len, myList))

Answer 2

With only 2 dimension:

[len(sub_list) for sub_list in myList]

Answer 3

Use a list comprehension:

>>> [len(l) for l in myList]
[1, 4, 1, 3, 2]

Another way is to use map:

>>> list(map(len, myList))
[1, 4, 1, 3, 2]

Answer 4

For a two dimension list like you have shown you can use the following code

res = [len(x) for x in myList]

or you could use a map function as follows

res = list(map(len, myList))