- 1Python String capitalize() – Capitalize First Letter of a String
- 2Python String casefold() – Case-Insensitive String Comparison
- 3Python String center() Method – Center Align a String with Padding
- 4Python String count() Method – Count Substring Occurrences
- 5Python string.encode() – Convert String to Bytes
- 6Python String endswith() – Check if a String Ends with Substring
- 7Python String expandtabs() – Replace Tabs with Spaces
- 8Python String find() – How to Locate Substrings Easily
- 9Python String index() Method – Find Position of a Substring
- 10Python String isalnum() Method – Check Alphanumeric Strings
- 11Python String isalpha() Method – Check for Alphabetic Characters
- 12Python String isascii() Method – Check for ASCII Characters
- 13Python String isdecimal() Method – Check if All Characters Are Decimals
- 14Python String isdigit() Method – Check If a String Has Only Digits
- 15Python String isidentifier() – Check for Valid Identifiers
- 16Python String islower() Method – Check for Lowercase Strings
- 17Python String isnumeric() Method – Check for Numeric Characters
- 18Python String isprintable() Method – Check Printable Characters
- 19Python String isspace() Method – Check for Whitespace Only
- 20Python String istitle() Method – Check for Title Case
- 21Python String isupper() Method – Check for Uppercase Letters
- 22Python String join() Method – Combine Strings Easily
- 23Python String ljust() Method – Left Justify a String with Spaces or Characters
- 24Python String lower() Method – Convert to Lowercase
- 25Python String lstrip() Method – Remove Leading Characters
- 26Python String maketrans() Method – Create Translation Tables
- 27Python String partition() Method – Split into Three Parts
- 28Python String replace() Method – Replace Substrings Easily
- 29Python String rfind() Method – Find Last Occurrence of Substring
- 30Python String rindex() Method – Find Last Occurrence of a Substring
- 31Python String rjust() Method – Right Justify a String
- 32Python String rpartition() Method – Split String from the Right
- 33Python String rsplit() Method – Split from the Right
- 34Python String rstrip() Method – Remove Trailing Characters
- 35Python String split() Method – Split Strings Easily
- 36Python String splitlines() Method – Split String by Line Breaks
- 37Python String startswith() Method – Check If a String Starts With
- 38Python String strip() Method – Remove Spaces from Ends
- 39Python String swapcase() Method – Convert Uppercase to Lowercase and Vice Versa
- 40Python String title() Method – Convert to Title Case
- 41Python String translate() Method – Replace Characters Using Mapping
- 42Python String upper() Method – Convert to Uppercase
- 43Python String zfill() Method – Pad String with Zeros
Python String upper() Method – Convert to Uppercase
Next Topic ⮕Python String zfill() Method – Pad String with Zeros
Python String upper()
Method
The upper() method in Python converts all lowercase characters in a string to uppercase. It is a built-in string method and is very useful when you want to standardize or compare text.
Syntax
string.upper()
Parameters:
- This method takes no parameters.
Returns:
- A new string with all characters in uppercase.
Example 1: Basic Usage
text = "hello world"
print(text.upper())
HELLO WORLD
Example 2: Mixed Case String
name = "Alice123"
print(name.upper())
ALICE123
Note: Numbers and symbols remain unchanged.
Use Cases
- To standardize user input (e.g., emails, usernames)
- For case-insensitive string comparisons
- To make output visually distinct (e.g., titles, warnings)
Does it change the original string?
No. Strings in Python are immutable. upper()
returns a new string — it does not modify the original.
word = "python"
new_word = word.upper()
print(word) # python
print(new_word) # PYTHON
Common Mistakes
- Trying to use
upper
without parentheses – remember it’s a method:string.upper()
- Assuming it changes the original string – you must assign the result if needed
Interview Tip
In coding tests, upper()
is handy for making string comparisons or normalizing data without worrying about the input case.
Summary
upper()
converts all characters in a string to uppercase.- Does not affect numbers or special characters.
- Returns a new string – original remains unchanged.
Practice Problem
Write a program that asks the user to enter their name and prints it in all capital letters.
name = input("Enter your name: ")
print("Your name in uppercase is:", name.upper())