Typeerror type numpy.ndarray doesnt define round method

Typeerror: type numpy.ndarray doesnt define round method

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In this article, we will deal with the error Typeerror: type numpy.ndarray doesnt define round method.

We will also look for the solutions to fix the error as well as a brief discussion of it.

What is Typeerror: type numpy.ndarray doesnt define round method

The TypeError: type numpy.ndarray doesn’t define round method error occurs when trying to access the ndarray object but it does not have a built-in method for rounding.

Here’s how this error reproduce:

import numpy as np

arr = np.array([1.11111111, 2.2222222, 3.3333333])
rounded_arr = round(arr)
print(rounded_arr)

Result:

TypeError: type numpy.ndarray doesn’t define __round__ method

In the next section, we will see solutions to this error…

How to fix Typeerror: type numpy.ndarray doesnt define round method

Here are the ways to fix this error Typeerror: type numpy.ndarray doesnt define round method.

Solution 1: Use list comprehension with round function

The first solution we can try in fixing type numpy.ndarray doesnt define round method is using list comprehension with built-in round() function.

For instance, we are going to create the numpy ndarray arr which contains the values of (1.1234567, 2.234567,3.9785612).

After which using the list comprehension and built-in function it should create another numpy ndarray rounded_arr which is now rounded items into 2 decimal places. 

import numpy as np

arr = np.array([1.1234567, 2.234567, 3.9785612])
rounded_arr = np.array([round(i, 2) for i in arr])
print(rounded_arr)

Result:

[1.12 2.23 3.98]

The above code shows that round(i,2) is a function that round each element i and arr array.

As a result, the output will be stored in the new rounded arr array.

If we print the rouned_arr function the result should be [1.12 2.23 3.98].

Solution 2: Use the np.around() method

The other solution we can try to fix type numpy.ndarray doesnt define round method is to use the np.around() method.

The numpy.around function is to round the arrays of numbers to desired decimal places. Particularly, it takes two arguments which are the array to be rounded and the number of decimal places to round off.

Moreover, we can utilize the np.around() fucntion to even round the given decimals.

Here is the example code we using the np.around() function:

import numpy as np

arr = np.array([1.12345675, 2.9874561, 3.32546987])
rounded_arr = np.around(arr, decimals=2)
print(rounded_arr)

Result:

[1.12 2.99 3.33]

Solution 3: Use custom function to apply the round() function

Here we should define a custom function to apply the round() function to each element of the numpy array.

import numpy as np

def round_array(arr, decimals=0):
    return np.array([round(num, decimals) for num in arr])

arr = np.array([1.23, 2.34, 3.45])
arr_rounded = round_array(arr, decimals=2)
print(arr_rounded)

Result:

[1.23 2.34 3.45]

Causes of Typeerror: type numpy.ndarray doesnt define round method

Here are some common causes of the TypeError “type numpy.ndarray doesn’t define round method”:

  1. Attempting to use the round function directly on a NumPy array.
  2. Having a variable that you think is a scalar value, but it is actually a NumPy array.
  3. Using an older version of NumPy that does not support the np.round function.
  4. Trying to perform a mathematical operation on a NumPy array that results in a non-scalar value.
  5. Using a variable that has not been properly defined or initialized.

Conclusion

In conclusion, the type numpy.ndarray doesnt define round method can be fixed using the np.around() function and can round the numbers on specified numbers of decimal places. Moreover, it is the default property of numpy ndarray object.

We hope that this article has helped you resolve this error and that you can now continue working on your Python projects without any issues.

Anyhow, if you are finding solutions to some errors you might encounter we also have TypeError can’t concat str to bytes.

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