Example
Input
'A'
Output
True
'A' is a single uppercase letter.
Full lesson preview
Is Single Character Uppercase
Check whether a given input is a single uppercase letter A-Z.
Python practice8 minControl Flow (If–Else Logic)BeginnerLast updated March 15, 2026
Problem statement
Write a function that takes one argument s and returns True if s is a string consisting of exactly one character and that character is an uppercase English letter (A-Z). For any other input (empty string, multiple characters, lowercase letters, digits, symbols), return False. Assume input will be a string.
Task
Implement a function that returns True only when the input is a single uppercase alphabetic character.
Examples
Input format
A single string s.
Output format
A boolean: True if s is a single uppercase alphabetic character, otherwise False.
Constraints
Input is a string. Consider only English alphabet uppercase letters A-Z.
Samples
Sample 1
Input
'a'
Output
False
Lowercase letters should return False.