Accessing Elements of a List You want to find individual elements of a list or change them.

Question

Accessing Elements of a List

You want to find individual elements of a list or change them.

Accepted Answer

Use the [] notation to access elements of a list by their position in the list. For example:

>>> a = [34, 'Fred', 12, False, 72.3]
>>> a[1]
'Fred'

Discussion

The list positions (indices) start at 0 for the first element.

As well as using the [] notation to read values out of a list, you can also use it to change values at a certain position. For example:

>>> a = [34, 'Fred', 12, False, 72.3]
>>> a[1] = 777
>>> a
[34, 777, 12, False, 72.3]

If you try to change (or, for that matter, read) an element of a list using an index that is too large, you will get an “Index out of range” error:

>>> a[50] = 777
Traceback (most recent call last):
File "", line 1, in
IndexError: list assignment index out of range
>>>

See Also

All the recipes between Recipes 6.1 and 6.11 involve the use of lists.

Question 6.2: Accessing Elements of a List You want to find individual ele......