[Fixed] Trying to fix a NumPy asscalar deprecation issue – Numpy

offsets = map(numpy.ndarray.item, offsets)
scale = map(numpy.ndarray.item, scale)

The Problem:

While updating an old Python script, a user encountered a deprecation error related to the ‘numpy.asscalar’ function in NumPy 1.16. The user attempted to use ‘numpy.ndarray.item’ as a replacement but faced another error. The objective is to find a suitable solution to address the deprecation issue and enable the code to run successfully.

The Solutions:

Solution 1: Replace numpy.asscalar with numpy.ndarray.item

The deprecated numpy.asscalar function can be replaced by numpy.ndarray.item to extract a scalar value from a NumPy array. This is because numpy.asscalar has been removed since NumPy 1.16, and the recommended replacement is numpy.ndarray.item.

The correct code should be:

offsets = map(numpy.ndarray.item, offsets)
scale = map(numpy.ndarray.item, scale)

This change ensures that the code is compatible with the latest version of NumPy without causing deprecation warnings.

Solution:

The deprecation of NumPy’s asscalar() function is a breaking change that affects code that relies on it. To fix this issue, you can use the item() method of NumPy arrays instead. Here’s a more detailed explanation:

Background:

NumPy’s asscalar() function was used to convert a single-element NumPy array into a Python scalar value. It was deprecated in favor of item(), which provides the same functionality.

Solution:

The solution is to modify the offsets and scale variables to use item() instead of asscalar(). To do this, you can use a map() function with item as the mapping function.

Code Fix:

import numpy

offsets = map(numpy.ndarray.item, offsets)
scale = map(numpy.ndarray.item, scale)

This code will apply the item() method to each element of the offsets and scale lists, effectively converting them into Python scalars.

Explanation:

• numpy.ndarray.item: This is the item() method of NumPy arrays, which is the recommended way to extract a scalar value from an array.
• map(): The map() function takes a function and a list as arguments, and applies the function to each element of the list. In this case, the item() method is applied to each element of the offsets and scale lists.

By following this fix, you can update your code to use the recommended item() method and resolve the deprecation error related to asscalar().

Solution 3: Using Numpy’s methods

We can use Numpy’s tolist() method to convert an array of Numpy scalars into a list of regular Python floats. Here’s how:

import numpy as np

# ... Your code here, up to the point where you have the `offsets` and `scale` lists.

# Convert the offsets and scale lists to regular Python floats using `tolist()`.
offsets = np.array(offsets).tolist()
scale = np.array(scale).tolist()

# ... Rest of your code.