Univariate Words X97337

Statement

Write a boolean function is_univariate_word(s) that, given a string $s$ , returns True if and only if $s$ consists of repetitions of one and the same letter, ignoring case differences. For instance: word xxXxXXx is univariate, but xxXxy is not.

Sample session

>>> is_univariate_word('xxXxxxXX')
True
>>> is_univariate_word('xyyyyYYY')
False
>>> is_univariate_word('y')
True
>>> is_univariate_word('yyyyx')
False

Information

Author: ProAl
Language: English
Translator: José Luis Balcázar
Original language: Spanish
Other languages: Catalan Spanish
Official solutions: Python
User solutions: Python