NumPy save() Method | Save Array to a File

The NumPy save() method is used to store NumPy arrays in a binary file format with the .npy extension, allowing data to be saved efficiently and loaded later without loss. This method preserves the structure and data type of the array, making it ideal for storing numerical datasets for reuse, sharing and fast access.

Example:

import numpy as np
a = np.arange(5)
np.save('array_file', a)

Syntax

numpy.save(file, arr, allow_pickle=True, fix_imports=True) 

Parameters:

• file: File or filename to which the data is saved. If the file is a string or Path, a .npy extension will be appended to the file name if it does not already have one. If the file is a file object, then the filename is unchanged. 
• allow_pickle: Allow saving object arrays using Python pickles. Reasons for disallowing pickles include security (loading pickled data can execute arbitrary code) and portability (pickled objects may not be loadable on different Python installations). Default: True 
• fix_imports: Only useful in forcing objects in object arrays on Python 3 to be pickled in a Python 2 compatible way. 
• arr: Array data to be saved. 
• Returns: Stores the input array in a disk file with '.npy' extension.

Examples

Let's understand the workings of numpy.save() method in these Python code and know how to use save() method of NumPy library.

To use numpy.save() function, you just need to pass the file name and array in the function.

Example 1

import numpy as np
a = np.arange(5)
print("a is:")
print(a)
np.save('geekfile', a)
print("the array is saved in the file data.npy")

a is:
[0 1 2 3 4]
the array is saved in the file data.npy

Example 2

import numpy as np
a = np.arange(5)
np.save('data.npy', a)
b = np.load('data.npy')

print("b is:")
print(b)
print("b is printed from data.npy")