Book Image

Practical Data Science with Python

By : Nathan George
Book Image

Practical Data Science with Python

By: Nathan George

Overview of this book

Practical Data Science with Python teaches you core data science concepts, with real-world and realistic examples, and strengthens your grip on the basic as well as advanced principles of data preparation and storage, statistics, probability theory, machine learning, and Python programming, helping you build a solid foundation to gain proficiency in data science. The book starts with an overview of basic Python skills and then introduces foundational data science techniques, followed by a thorough explanation of the Python code needed to execute the techniques. You'll understand the code by working through the examples. The code has been broken down into small chunks (a few lines or a function at a time) to enable thorough discussion. As you progress, you will learn how to perform data analysis while exploring the functionalities of key data science Python packages, including pandas, SciPy, and scikit-learn. Finally, the book covers ethics and privacy concerns in data science and suggests resources for improving data science skills, as well as ways to stay up to date on new data science developments. By the end of the book, you should be able to comfortably use Python for basic data science projects and should have the skills to execute the data science process on any data source.
Table of Contents (30 chapters)
1
Part I - An Introduction and the Basics
4
Part II - Dealing with Data
10
Part III - Statistics for Data Science
13
Part IV - Machine Learning
21
Part V - Text Analysis and Reporting
24
Part VI - Wrapping Up
28
Other Books You May Enjoy
29
Index

Probability basics

Probability is all about uncertainty. For example, if we flip a normal coin, we're never sure if it will land on one side or the other (heads or tails). However, we can estimate the probability of the coin landing on heads with a probability function.

The simple frequentist definition of probability and a probability function is that we count the number of times the desired event happens over the total number of outcomes. In the case of a coin toss, we could flip the coin 10 times, count the number of heads, and divide by 10. Most of the time we will have something close to 5/10, or 50%. So, our probability function could be thought of as each coin flip (action, or event) resulting in a 50% chance of landing on heads (our desirable outcome). We can write the equation for our probability function as and . Our total probability across all possible (discrete) events must sum to 1 in probability theory, as it does here.

Figure 8.1: The probabilities...