Is arr.__len__() the preferred way to get the length of an array in Python?

Question

In Python, is the following the only way to get the number of elements?

arr.__len__()

If so, why the strange syntax?

Answer 1

Just use len(arr):

>>> import array
>>> arr = array.array('i')
>>> arr.append('2')
>>> arr.__len__()
1
>>> len(arr)
1