List operations

Slicing is one way of locating certain items in a list. For example, myList[1:3] will print item 1 and item 2 (remember lists start at item 0). len() can be used to find the length of a list.

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my_list = [5,7,12,9,4,6,8,9]
length = len(my_list)
print(length)

my_list.reverse() #can be used to reverse the list

Adding and taking away from a list of items

Here are some useful functions:

  • my_list.append(“lion”) - will add the item lion to the end of the list
  • my_list.insert(3,”lion”) - will add “Lion” before item 3 in the list
  • my_list.pop(5) - will delete the 5th item

This video clip shows how to add and delete items from a list


Exercise - A FOR loop and a list

What do you think this function will do? Type in the code and see if it did what you thought it would.

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def mystery():
    animals =["dog","cat","fox","rabbit","deer","pig"]
    for counter in range(len(animals)):
        print("Animal {0} is {1}".format(counter,animals[counter]))

Now make some improvements to the code.