A common problem we need to solve is how to swap two values
For example if we have to variables x and y,
we might want to swap the
the values.
x = 123
y = 456
print('Start values: a = {} b = {} '.format(x, y))
temp = x
x = y
y = temp
print('Finish values: a = {} b = {} '.format(x, y))
A better, more succinct method is to use the cool 'tuple unpacking'
x = 123
y = 456
print('Start values: a = {} b = {} '.format(x, y))
x, y = y, x
print('Finish values: a = {} b = {} '.format(x, y))
