[FIXED] How do I count the occurrence of a certain item in an ndarray?

Issue

How do I count the number of 0s and 1s in the following array?

y = np.array([0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1])

---

y.count(0) gives:

numpy.ndarray object has no attribute count

Solution

a = numpy.array([0, 3, 0, 1, 0, 1, 2, 1, 0, 0, 0, 0, 1, 3, 4])
unique, counts = numpy.unique(a, return_counts=True)
dict(zip(unique, counts))

# {0: 7, 1: 4, 2: 1, 3: 2, 4: 1}

Non-numpy way:

Use collections.Counter;

import collections, numpy
a = numpy.array([0, 3, 0, 1, 0, 1, 2, 1, 0, 0, 0, 0, 1, 3, 4])
collections.Counter(a)

# Counter({0: 7, 1: 4, 3: 2, 2: 1, 4: 1})

Answered By - Ozgur Vatansever