As an exercise, write a function that takes a string as an argument and outputs the letters backward, one per line.

revFruit.py

fruit = "banana"

def revFruit(fruit):
	index = len(fruit)-1
	while index >= 0:
		letter = fruit[index]
		print letter
		index = index - 1

Returns and prints letters of fruit backwards.

>>> revFruit(fruit)
a
n
a
n
a
b

http://pythontutor.com/visualize.html#code=fruit+%3D+%22banana%22%0A%0Adef+revFruit(fruit)%3A%0A%09index+%3D+len(fruit)-1%0A%09while+index+%3E%3D+0%3A%0A%09%09letter+%3D+fruit%5Bindex%5D%0A%09%09print+letter%0A%09%09index+%3D+index+-+1%0A++++++++%0ArevFruit(fruit)%0A&mode=display&cumulative=false&py=2&curInstr=28