count number of 1s in listpython code example

Example 1: how to find the number of times a number appears in python

dict((i, a.count(i)) for i in a)

Example 2: count occurrence in array python

arr = np.array( [1, 2, 3, 2, 1, 2])
occ = np.count_nonzero(arr==0)
print(occ)
0
occ = np.count_nonzero(arr==1)
print(occ)
2