## Question

Asked By – mflowww

How do I count the number of `0`

s and `1`

s 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`

**Now we will see solution for issue: How do I count the occurrence of a certain item in an ndarray? **

## Answer

Using `numpy.unique`

:

```
import numpy
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 method** using `collections.Counter`

;

```
import collections, numpy
a = numpy.array([0, 3, 0, 1, 0, 1, 2, 1, 0, 0, 0, 0, 1, 3, 4])
counter = collections.Counter(a)
>>> counter
Counter({0: 7, 1: 4, 3: 2, 2: 1, 4: 1})
```

This question is answered By – Ozgur Vatansever

**This answer is collected from stackoverflow and reviewed by FixPython community admins, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0 **