List indexing
The items in a list are indexed starting from zero:
names = ['Maria', 'Mariano', 'Anna', 'Antonino']
To access individual items in the list, use square brackets:
grandmother = names[2]
In this case, grandmother
would have the value Anna
. Likewise, names[0]
would be Maria
.
Going past the end of the list
The last item is at len(names) - 1
:
last_name = names[len(names) - 1]
Trying to index past the end of a list will create an error:
names[7]
The error you will see:
IndexError: list index out of range
Negative indexing
We can count backwards from the end using negative numbers, so names[-1]
is
Antonino
.
Likewise, names[-3]
is Mariano
.
Mutating lists
Lists are mutable, meaning you can change them:
if __name__ == '__main__':
names = ['Maria', 'Mariano', 'Anna', 'Antonino']
names[1] = 'Carmelo'
print(names)
This will print:
['Maria', 'Carmelo', 'Anna', 'Antonino']