[Solved] The following code throws an error. What is the problem?import numpy as np arr = [1, 2, 3, 4] result = np.mean(arr, axis=1) print(result) | NumPy

NumPy - Aggregation Functions

The following code throws an error. What is the problem?

import numpy as np
arr = [1, 2, 3, 4]
result = np.mean(arr, axis=1)
print(result)

Anp.mean() cannot be used on lists

BThe list is 1D, so axis=1 is invalid

CMissing parentheses in np.mean

DThe variable name 'arr' is reserved

Step-by-Step Solution

Solution:

Step 1: Check the array shape
The variable arr is a 1D list with shape (4,). Axis 1 does not exist in 1D data.
Step 2: Understand axis parameter
Axis=1 means operate along columns in 2D or higher arrays. Using axis=1 on 1D data causes an error.
Final Answer:
The list is 1D, so axis=1 is invalid -> Option B
Quick Check:
Axis must exist in array shape [OK]

Quick Trick: Check array dimensions before using axis [OK]

Common Mistakes:

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