Course Content
Python Data Structures
Python Data Structures
List Indexing
In Python, lists allow for element indexing. This means we can access each item in the list by its index. Remember, indexing in lists starts at 0
. So, the first item is at index 0
, the second at index 1
, and so forth.
list_A = ['red', 'green', 'blue', 'yellow', 'black'] # Getting the first element print(list_A[0]) # Getting the third element print(list_A[2])
We've covered positive indexing, but there's also something called negative indexing. Negative indexing starts from the end of the list. For instance, index -1
refers to the last item, index -2
points to the second-to-last item, and so on.
list_A = ['red', 'green', 'blue', 'yellow', 'black'] # Getting the last element print(list_A[-1]) # Getting the fourth element print(list_A[3], list_A[-2])
Let's put this into practice.
Task
You're given: list_1 = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']
. Your task is to extract the first, third, fifth, and seventh items from this list and create a new list with these items, using positive indices only.
Thanks for your feedback!
List Indexing
In Python, lists allow for element indexing. This means we can access each item in the list by its index. Remember, indexing in lists starts at 0
. So, the first item is at index 0
, the second at index 1
, and so forth.
list_A = ['red', 'green', 'blue', 'yellow', 'black'] # Getting the first element print(list_A[0]) # Getting the third element print(list_A[2])
We've covered positive indexing, but there's also something called negative indexing. Negative indexing starts from the end of the list. For instance, index -1
refers to the last item, index -2
points to the second-to-last item, and so on.
list_A = ['red', 'green', 'blue', 'yellow', 'black'] # Getting the last element print(list_A[-1]) # Getting the fourth element print(list_A[3], list_A[-2])
Let's put this into practice.
Task
You're given: list_1 = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']
. Your task is to extract the first, third, fifth, and seventh items from this list and create a new list with these items, using positive indices only.
Thanks for your feedback!
List Indexing
In Python, lists allow for element indexing. This means we can access each item in the list by its index. Remember, indexing in lists starts at 0
. So, the first item is at index 0
, the second at index 1
, and so forth.
list_A = ['red', 'green', 'blue', 'yellow', 'black'] # Getting the first element print(list_A[0]) # Getting the third element print(list_A[2])
We've covered positive indexing, but there's also something called negative indexing. Negative indexing starts from the end of the list. For instance, index -1
refers to the last item, index -2
points to the second-to-last item, and so on.
list_A = ['red', 'green', 'blue', 'yellow', 'black'] # Getting the last element print(list_A[-1]) # Getting the fourth element print(list_A[3], list_A[-2])
Let's put this into practice.
Task
You're given: list_1 = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']
. Your task is to extract the first, third, fifth, and seventh items from this list and create a new list with these items, using positive indices only.
Thanks for your feedback!
In Python, lists allow for element indexing. This means we can access each item in the list by its index. Remember, indexing in lists starts at 0
. So, the first item is at index 0
, the second at index 1
, and so forth.
list_A = ['red', 'green', 'blue', 'yellow', 'black'] # Getting the first element print(list_A[0]) # Getting the third element print(list_A[2])
We've covered positive indexing, but there's also something called negative indexing. Negative indexing starts from the end of the list. For instance, index -1
refers to the last item, index -2
points to the second-to-last item, and so on.
list_A = ['red', 'green', 'blue', 'yellow', 'black'] # Getting the last element print(list_A[-1]) # Getting the fourth element print(list_A[3], list_A[-2])
Let's put this into practice.
Task
You're given: list_1 = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']
. Your task is to extract the first, third, fifth, and seventh items from this list and create a new list with these items, using positive indices only.