Outside of English, upper and lower case isn't that simple. Consider German. Lower case letter "ß" was converted to two upper case letters, "SS" or "SZ", unti

Outside of English, upper and lower case isn't that simple. Consider German. Lower case letter "ß" was converted to two upper case letters, "SS" or "SZ", until fairly recently, when a new character "ẞ" was officially added. Much software still uppercases "ß" to "SS". For example: $ python3 -c 'print("große".upper())' GROSSE Consider Turkish. Upper case letter "I" converts to lower case "i" in English, but in Turkish the same letter converts to lower case "ı" (no dot). Lower case letter "i" converts to upper case "I" in English, but in Turkish the same letter converts to upper case "İ" (with a dot). So you have to know which language you're using. It's not enough to know the character. https://en.wikipedia.org/wiki/ß https://en.wikipedia.org/wiki/ß https://en.wikipedia.org/wiki/Dotted_and_dotless_I_in_computing https://en.wikipedia.org/wiki/Dotted_and_dotless_I_in_comput...