TypeError: only integer scalar arrays can be converted to a scalar

I'm a new learner, and I am learning based on some videos. In the video the code faced no problem. However, I faced with a Traceback. I can't figure out what the problem is. Here is my code:

import numpy as np
arr_bis = np.array ([[1,2,3],[7,1,6],[9,6,3]])
arr1 = arr_bis[:,1]
arr2 = arr_bis[:,2]
print (f"ARR1{arr1}")
print (f"ARR2{arr2}")
print (np.concatenate(arr1, arr2), axis = 0)

I want to concatenate two arrays. This is the error: Traceback (most recent call last): File "", line 7, in File "<array_function internals>", line 180, in concatenate TypeError: only integer scalar arrays can be converted to a scalar index

Can somebody tell me what is the problem please?

CodePudding user response：

You are using numpy.concatenate incorrectly.

The first parameter should be an iterable of the arrays to concatenate

numpy.concatenate((a1, a2, ...), axis=0, out=None, dtype=None, casting="same_kind")

np.concatenate((arr1, arr2), axis=0)

output: array([2, 1, 6, 3, 6, 3])

In your case, not only you passed arr2 as the second parameter, but you also passed the axis=0 parameter to the wrong function (here to print):

print(                             # print function
      np.concatenate(arr1, arr2),  # first parameter of print
                                   # with incorrect calling
      axis = 0                     # second (invalid) parameter of print
)

CodePudding user response：

You missed a parenthesis in your print.

print (np.concatenate(arr1, arr2), axis = 0)

should be

print (np.concatenate((arr1, arr2), axis = 0))