# TypeError: Iteration Over a 0-D Array in Python

Python’s Numpy library works with arrays and performs Mathematical operations. Numpy arrays require a list of data to convert the information into a `ndarray`.

If we pass anything else, e.g., an iterator, they will result in an error named `TypeError: iteration over a 0-d array`.

## Numpy Arrays and Their Dimension

Numpy’s primary object is `ndarray`, an array object. It uses a typical Python array or list to create the `ndarray`.

The `ndarray` can now utilize all the functions available in Numpy.

Numpy can have arrays of different dimensions. We can check the dimension of `ndarray` using the `ndim` attribute.

Example Code:

``````#Python 3.x
import numpy as np
array = np.array(3)
array1 = np.array([3,1])
array2 = np.array([[1,3],[4,2]])
print(array.ndim)
print(array1.ndim)
print(array2.ndim)
``````

Output:

``````#Python 3.x
0
1
2
``````

## the `TypeError: iteration over a 0-d array` in Python

It will give the error if we pass an iterator instead of a list. Because Numpy arrays need an array to make their `ndarray`, an iterator would not work correctly here.

Example Code:

``````#Python 3.x
import numpy as np
dictionary = {}
keys,values = np.array(dictionary.items())
``````

Output:

``````#Python 3.x
TypeError: iteration over a 0-d array
``````

## Fix the `TypeError: iteration over a 0-d array` in Python

We can convert the iterator into a list when supplying it to the `np.array()` function. Getting a list as a parameter would make the function work correctly.

In the following code, we have created a dictionary. To make a `ndarray` using this dict, first, we have to convert the dictionary to a list and pass it as an argument to `nd.array()`.

Example Code:

``````#Python 3.x
import numpy as np
data = {
"Jhon": 90,
"Alia": 80,
"Jack": 70,
}
keys, values = np.array(list(data.items())).T
print(keys)
print(values)
``````

Output:

``````#Python 3.x
['Jhon' 'Alia' 'Jack']
['90' '80' '70']
``````
Author: Fariba Laiq

I am Fariba Laiq from Pakistan. An android app developer, technical content writer, and coding instructor. Writing has always been one of my passions. I love to learn, implement and convey my knowledge to others.

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