Python| kee/value pair not incrementing : I'm fairly knew to Python so I'm following along using the Head First Python 2nd edition. I come across an example I'm completely stumped on and I was wondering that I'm doing wrong as I'm following along just right. I've done some research on the internet on how to properly increment a key/value pair in dictionary and I seem to be doing it right so not sure what is going on. Here is what I have running: Python 3.5.2. on Mac OS Sierra. 

fruits = {} 
fruits['apples'] = 10
if 'bananas' in fruits:
    fruits['bananas'] += 1
else:
    fruits['bananas'] = 1

Initially when I print fruits it show bananas 1, apples 10 but the second time I print fruits it should show bananas 2 but it doesn't and only show 1. Its not increasing. 

Thank you for your knowledge.