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Python Python Basics (2015) Python Data Types List cleanup

index error

whats wrong with the code?

messy = [5, 2, 8, 1, 3]
del messy[8]

1 Answer

28,558 Points

The thing you write in the brackets after "messy" is not the value you want to remove from the list but the index of the item you want removed.

In other words if you wanted to remove the first item from the list you would pass in 0, since list indexes start at 0 not at 1. If you wanted to delete the second item you would pass in 1, and so on.

So the thing that is wrong with your code is that you are asking Python to delete the 9th item of the list, since there are only 5 items you get an "out of range" error, since the value you provided is indeed higher than the actual number of items in the list.

Here is an example of how to use the del keyword with a list:

exampleList = [4, 6, 7, 9, 10, 53, 100]
# If I want to delete the 10 from the list I would write:
del exampleList[4]
# Since 10 is the fifth item which means it has an index of 4, since the index starts at 0.