NumPy in a Nutshell

NumPy in a Nutshell

0%

1. Getting Started with NumPy

In this section we will get acquainted with what the NumPy library is, as well as learn how to create an array.

Function array()

Basic Array Creation Quiz

2. Dimensions in Arrays

In this section we will get acquainted with arrays of different dimensions, and understand the difference between them.

Mathematical Operations with 1-D Arrays

Multidimensional Arrays Quiz

3. Indexing and Slicing

In this section we should recall what slices are and learn how to make them for arrays of different dimensions. We shall also learn to refer to elements in an array using their indexes.

Access Array Elements

Match Math Operations

Access 2-D and 3-D Arrays

Match the Slicing

Negative Indexing

Match the Indices

Get One Dimensional Array Using Slice and Only Positive Indexes

Get One Dimensional Array Using Only Negative Indexes

4. Important Functions

In this section we will learn how to reshape arrays and also how to concatenate an array. Moreover we will learn how to sort an array. Also we will learn about such an interesting method that is often used for arrays, namely: copy().

Course Content

NumPy in a Nutshell

NumPy in a Nutshell

1. Getting Started with NumPy

What is NumPy?Function array()Basic Array Creation Quiz

2. Dimensions in Arrays

1-D Arrays Mathematical Operations with 1-D Arrays 2-D Arrays 3-D Arrays Multidimensional Arrays Quiz

3. Indexing and Slicing

Access Array Elements Match Math Operations Access 2-D and 3-D Arrays Match the Slicing Negative Indexing Match the Indices Get One Dimensional Array Using Slice and Only Positive Indexes Get One Dimensional Array Using Only Negative Indexes

4. Important Functions

Reshaping Flattening Joining Sorting Arrays Copying Arrays

Negative Indexing

We discussed positive indexing, but there is also negative indexing. Negative indexing starts from the end, with index -1 referring to the last element, index -2 referring to the second-to-last element, and so on.


              12345
            
import numpy as np

arr = np.array([[1, 3, 5, 7, 9], [2, 4, 6, 8, 10]])

print(arr[-1 , -1])

This example illustrates how to retrieve a value of 10 from a given two-dimensional array using negative indexing.

The first index determines the row we choose (-1 refers to the last row), while the second index corresponds to the element we select within that row (-1 is the last one). As a result, we obtain a value of 10. Run the code above to verify it.

Task

Swipe to show code editor

You have the following array: [[-4, 3, 1], [2, 10, -4]]. Access the value 10.

Let's give it a try. Use only negative indices.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 3. Chapter 5

toggle bottom row

Negative Indexing

We discussed positive indexing, but there is also negative indexing. Negative indexing starts from the end, with index -1 referring to the last element, index -2 referring to the second-to-last element, and so on.


              12345
            
import numpy as np

arr = np.array([[1, 3, 5, 7, 9], [2, 4, 6, 8, 10]])

print(arr[-1 , -1])

This example illustrates how to retrieve a value of 10 from a given two-dimensional array using negative indexing.

The first index determines the row we choose (-1 refers to the last row), while the second index corresponds to the element we select within that row (-1 is the last one). As a result, we obtain a value of 10. Run the code above to verify it.

Task

Swipe to show code editor

You have the following array: [[-4, 3, 1], [2, 10, -4]]. Access the value 10.

Let's give it a try. Use only negative indices.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 3. Chapter 5

Switch to desktop for real-world practiceContinue from where you are using one of the options below

some-alt