How to make a NumPy array read-only? Last Updated : 04 Nov, 2022 Comments Improve Suggest changes 3 Likes Like Report See More Let's discuss how to make NumPy array immutable i.e that can not be rewritten or can't be changed. This can be done by setting a writable flag of the NumPy array to false. Syntax: array.flags.writable=False This set the writable flag to false and hence array becomes immutable i.e read-only. See the example below Example: Python import numpy as np a = np.zeros(11) print("Before any change ") print(a) a[1] = 2 print("Before after first change ") print(a) a.setflags(write=False) print("After making array immutable on attempting second change ") a[1] = 7 Output: Before any change [0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.] Before after first change [0. 2. 0. 0. 0. 0. 0. 0. 0. 0. 0.] After making array immutable on attempting second change Traceback (most recent call last): File "gfg9.py", line 11, in <module> a[1]=7 ValueError: assignment destination is read-only Create Quiz Comment S shivanshsaxena1 Follow 3 Improve S shivanshsaxena1 Follow 3 Improve Article Tags : Python Python-numpy Python numpy-arrayManipulation Explore Python FundamentalsPython Introduction 2 min read Input and Output in Python 4 min read Python Variables 4 min read Python Operators 4 min read Python Keywords 2 min read Python Data Types 8 min read Conditional Statements in Python 3 min read Loops in Python - For, While and Nested Loops 5 min read Python Functions 5 min read Recursion in Python 4 min read Python Lambda Functions 5 min read Python Data StructuresPython String 5 min read Python Lists 4 min read Python Tuples 4 min read Python Dictionary 3 min read Python Sets 6 min read Python Arrays 7 min read List Comprehension in Python 4 min read Advanced PythonPython OOP Concepts 11 min read Python Exception Handling 5 min read File Handling in Python 4 min read Python Database Tutorial 4 min read Python MongoDB Tutorial 3 min read Python MySQL 9 min read Python Packages 10 min read Python Modules 3 min read Python DSA Libraries 15 min read List of Python GUI Library and Packages 3 min read Data Science with PythonNumPy Tutorial - Python Library 3 min read Pandas Tutorial 4 min read Matplotlib Tutorial 5 min read Python Seaborn Tutorial 3 min read StatsModel Library - Tutorial 3 min read Learning Model Building in Scikit-learn 6 min read TensorFlow Tutorial 2 min read PyTorch Tutorial 6 min read Web Development with PythonFlask Tutorial 8 min read Django Tutorial | Learn Django Framework 7 min read Django ORM - Inserting, Updating & Deleting Data 4 min read Templating With Jinja2 in Flask 6 min read Django Templates 5 min read Build a REST API using Flask - Python 3 min read Building a Simple API with Django REST Framework 3 min read Python PracticePython Quiz 1 min read Python Coding Practice 1 min read Python Interview Questions and Answers 15+ min read Like