Setting an array element with a sequence [SOLVED]

This article discusses the generation of error “setting an array element with a sequence”, how it can occur, what causes this error and how to fix it.

This error is generated while using the numpy library while working with numpy arrays.

Numpy is a python library that is used to deal with large numbers and matrices. It consists of high level mathematical functions to deal with numbers and functions.

 

Why does ValueError : setting an array element with a sequence occur?

The error setting an array element with a sequence occurs when the datatype of all the elements of the numpy array are not the same as the datatype passed to the array.

Example

import numpy as np
array= [1, 2, 4, [5, [6, 7]]]
np.array(array, dtype=int)
print("the int array is :",array)

The output error that is generated is:

 ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (4,) + inhomogeneous part.

 

How to Prevent ValueError : setting an array element with a sequence?

Use a object data type

Since the error occurs due to use of different datatypes in the numpy array elements, we can set the numpy array data type to object, it is a common data type that accepts all elements.

The code becomes :

import numpy as np
array= [1, 2, 4, [5, [6, 7]]]
np.array(array, dtype=object)
print("the int array is :",array)

The output of this code is :

the int array is : [1, 2, 4, [5, [6, 7]]]

Set the datatype and check

You can set the datatype, store it in a variable and then check the array elements, if they are not the same datatype, ignore, else print.

# setting an array element with a sequence
import numpy
array1 = ["go", "linuxCloud"]
Data_type = str

array2 = numpy.array(array1, dtype=Data_type)
Variable = ["go", 1]

if array2.dtype == type(Variable):
    array2[1] = Variable
else:
    print("not same")
print(array2)

The output of this code is :

not same
['go' 'linuxCloud']

 

Conclusion

In this article we learned about the fix of the error setting an array element with a sequence. How it is generated and how this error can be avoided or fixed.

 

Further Reading

Numpy 
AttributeError: module 'numpy' has no attribute 'loads'
ValueError: setting an array element with a sequence