The “NameError: name ‘numpy’ is not defined” error message is typically encountered when trying to use the NumPy library in Python but the library has not been imported or has not been imported correctly.

To fix this error, you need to ensure that you have installed the NumPy library in your environment and that you have imported it correctly in your code. Here are some steps you can follow:

Install NumPy: If you haven’t installed NumPy yet, you can install it using pip, the Python package manager, by running the following command in your terminal or command prompt:

pip install numpy

Import NumPy: Once you have installed NumPy, you need to import it in your Python code before you can use it. You can do this by adding the following line at the beginning of your code:

import numpy as np

This imports the NumPy library and gives it an alias “np” that you can use to access NumPy functions and classes.

Use NumPy: You can now use NumPy functions and classes in your code. For example, to create a NumPy array, you can write:

import numpy as np my_array = np.array([1, 2, 3])

Make sure to save your code after making the changes and run it again. This should fix the “NameError: name ‘numpy’ is not defined” error and allow you to use NumPy in your code.