np.load

np.save('data.npy', num_arr) # save
new_num_arr = np.load('data.npy') # load

Here is what the above code is Doing:
1. Create a NumPy array.
2. Save the array to a file called ‘data.npy’.
3. Load the array from the file.

The file ‘data.npy’ is a binary file that contains the data in the NumPy array.

The file is not human-readable, but it can be read by NumPy.

The file ‘data.npy’ is about 1/4 the size of the original array.

The file ‘data.npy’ can be read by NumPy, but it cannot be read by a text editor.

The file ‘data.npy’ can be read by a text editor if it is first converted to a text file.

The file ‘data.npy’ can be read by a text editor if it is first converted to a CSV file.

The file ‘data.npy’ can be read by a text editor if it is first converted to a JSON file.