Loops

Loops are a way to repeatedly execute some code. Here's an example:

In [1]:

planets = ['Mercury', 'Venus', 'Earth', 'Mars', 'Jupiter', 'Saturn', 'Uranus', 'Neptune']
for planet **in** planets:
    print(planet, end=' ') *# print all on same line*

Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune

The for loop specifies.

• the variable name to use (in this case, planet)
• the set of values to loop over (in this case, planets)

You use the word "in" to link them together.

The object to the right of the "in" can be any object that supports iteration. Basically, if it can be thought of as a group of things, you can probably loop over it. In addition to lists, we can iterate over the elements of a tuple:

In [2]:

multiplicands = (2, 2, 2, 3, 3, 5)
product = 1
for mult **in** multiplicands:
    product = product * multproduct

Out [2]: