the upper(and lower(string methods return new string where all the letters in the original string have been converted to uppercase or lowercaserespectively nonletter characters in the string remain unchanged enter the following into the interactive shellspam 'helloworld!spam spam upper(spam 'helloworld!spam spam lower(spam 'helloworld!note that these methods do not change the string itself but return new string values if you want to change the original stringyou have to call upper(or lower(on the string and then assign the new string to the variable where the original was stored this is why you must use spam spam upper(to change the string in spam instead of simply spam upper((this is just like if variable eggs contains the value writing eggs does not change the value of eggsbut eggs eggs does the upper(and lower(methods are helpful if you need to make caseinsensitive comparison for examplethe strings 'greatand 'greatare not equal to each other but in the following small programit does not matter whether the user types greatgreator greatbecause the string is first converted to lowercase print('how are you?'feeling input(if feeling lower(='great'print(' feel great too 'elseprint(' hope the rest of your day is good 'when you run this programthe question is displayedand entering variation on greatsuch as greatwill still give the output feel great too adding code to your program to handle variations or mistakes in user inputsuch as inconsistent capitalizationwill make your programs easier to use and less likely to fail how are yougreat feel great too you can view the execution of this program at /convertlowercasethe isupper(and islower(methods will return boolean true value if the string has at least one letter and all the letters manipulating strings