upper() function - NumPy Last Updated : 27 Sep, 2025 Suggest changes Share Like Article Like Report The numpy.char.upper() function is used to convert all characters in the elements of a NumPy string array to uppercase. It works element-wise and returns a new array with the modified strings.This example shows how to use np.char.upper() to convert lowercase characters into uppercase. Python import numpy as np arr = np.array(['hello world']) res = np.char.upper(arr) print(res) Output['HELLO WORLD'] Syntaxnumpy.char.upper(arr)Parameters: arr (array_like) -> Input array of strings.Return Value: ndarray -> Array with all string elements converted to uppercase.ExamplesExample 1: In this example, we convert alphanumeric strings to uppercase. Python import numpy as np arr = np.array(['p4q r', '4q rp', 'q rp4', 'rp4q']) res = np.char.upper(arr) print("Array:", arr) print("Result:", res) OutputArray: ['p4q r' '4q rp' 'q rp4' 'rp4q'] Result: ['P4Q R' '4Q RP' 'Q RP4' 'RP4Q'] Example 2: In this example, we convert a simple word array into uppercase. Python import numpy as np arr = np.array(['geeks', 'for', 'geeks']) res = np.char.upper(arr) print("Array:", arr) print("Result:", res) OutputArray: ['geeks' 'for' 'geeks'] Result: ['GEEKS' 'FOR' 'GEEKS'] Example 3: Here, we apply upper() to sentences with mixed cases. Python import numpy as np arr = np.array(['NumPy is Powerful', 'python is fun']) res = np.char.upper(arr) print("Array:", arr) print("Result:", res) OutputArray: ['NumPy is Powerful' 'python is fun'] Result: ['NUMPY IS POWERFUL' 'PYTHON IS FUN'] J jana_sayantan Follow 0 Article Tags : Python Python-numpy Python numpy-String Operation Explore Python FundamentalsPython Introduction 2 min read Input and Output in Python 4 min read Python Variables 5 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 2 min read Python MySQL 9 min read Python Packages 10 min read Python Modules 7 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 15+ min read StatsModel Library- Tutorial 4 min read Learning Model Building in Scikit-learn 8 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 7 min read Python | Build a REST API using Flask 3 min read How to Create a basic API using Django Rest Framework ? 4 min read Python PracticePython Quiz 1 min read Python Coding Practice 1 min read Python Interview Questions and Answers 15+ min read My Profile ${profileImgHtml} My Profile Edit Profile My Courses Join Community Transactions Logout Like