Course Content
NumPy in a Nutshell
1. Getting Started with NumPy
3. Indexing and Slicing
4. Important Functions
NumPy in a Nutshell
Access Array Elements
Both in lists and in arrays, elements are accessed using regular square brackets. Let's remember the difference between indexing and slicing.
- In order to get a single element, we just need to specify the index of this element in square brackets (start counting from 0).
- Therefore, in order to obtain a sequence from the original array, we should use slices.
We start with a simple indexing. Let's look at the next image.

Let's see how it works with examples.
Get the first element from the following array:
Get the second element from the following array:
Get the third and the fourth elements from the following array and add them:
Now it's time to look at using slicing. First, let's look at the syntax of slicing: array[start:end:step]
respectively:
- start - the index from which to start slicing.
- end - the index till which the slicing ends (! this index is not included).
- step - this parameter determines the increments between the indices.
Let's look at the next image.

It's time to practice.
Task
Get the first and the last elements from the following array [13, 99, 11, 23, 4, 41]
and multiply them. Please, use positive indexing.
Everything was clear?