string methods don' just work on string literals you can also use lower(on string assigned to variablename "jean-luc picardname lower('jean-luc picardthe opposite of lower(is upper()which converts every character in string to uppercasename upper('jean-luc picardcompare the upper(and lower(string methods to the len(function you saw in the last section aside from the different results of these functionsthe important distinction here is how they're used len(is stand-alone function if you want to determine the length of the name stringthen you call the len(function directlylen(name on the other handupper(and lower(must be used in conjunction with string they do not exist independently removing whitespace from string whitespace is any character that is printed as blank space this includes things like spaces and line feedswhich are special characters that move output to new line sometimes you need to remove whitespace from the beginning or end of string this is especially useful when working with strings that come from user inputwhich may include extra whitespace characters by accident