Excuse me, this is a library

Excuse me, this is a library#

Another string method is isupper, and is documented as follows:

str.isupper()

Returns True if the string is at least one character long and all cased characters are uppercase

Example usage:

>>> all_upper = "HELLO!"
>>> all_upper.isupper()
True
>>> not_all_upper = "Hello!"
>>> not_all_upper.isupper()
False

For this challenge, define a function called quieter_please that takes in one string argument and checks if the string is all uppercase. If it is all upper case, convert the string to all lowercase and return this lowercased string. If the argument string is not all uppercase, return this same string, unmodified.

Note: In Step 1, we learned about the upper() method, which produces a new string with all letters converted to uppercase. There is also a lower() method, which will produce a new string with all letters converted to lowercase.

Sample Input 1:

MAKE ME LOWERCASE, PLEASE!

Sample Output 1:

make me lowercase, please!

Sample Input 2:

i'm already lowercase

Sample Output 2:

i'm already lowercase

Sample Input 3:

I have both UPPERcase and lowercase

Sample Output 3:

I have both UPPERcase and lowercase