first argument passed to the method is the key to check forand the second argument is the value to set at that key if the key does not exist if the key does existthe setdefault(method returns the key' value enter the following into the interactive shellspam {'name''pooka''age' spam setdefault('color''black''blackspam {'color''black''age' 'name''pooka'spam setdefault('color''white''blackspam {'color''black''age' 'name''pooka'the first time setdefault(is calledthe dictionary in spam changes to {'color''black''age' 'name''pooka'the method returns the value 'blackbecause this is now the value set for the key 'colorwhen spam setdefault('color''white'is called nextthe value for that key is not changed to 'white'because spam already has key named 'colorthe setdefault(method is nice shortcut to ensure that key exists here is short program that counts the number of occurrences of each letter in string open the file editor window and enter the following codesaving it as charactercount pymessage 'it was bright cold day in apriland the clocks were striking thirteen count {for character in messagecount setdefault(character count[charactercount[character print(countyou can view the execution of this program at the program loops over each character in the message variable' stringcounting how often each character appears the setdefault(method call ensures that the key is in the count dictionary (with default value of so the program doesn' throw keyerror error when count[charactercount[character is executed when you run this programthe output will look like this{' ',' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' dictionaries and structuring data