Book Image

Python Data Analysis - Third Edition

By : Avinash Navlani, Ivan Idris
5 (1)
Book Image

Python Data Analysis - Third Edition

5 (1)
By: Avinash Navlani, Ivan Idris

Overview of this book

Data analysis enables you to generate value from small and big data by discovering new patterns and trends, and Python is one of the most popular tools for analyzing a wide variety of data. With this book, you’ll get up and running using Python for data analysis by exploring the different phases and methodologies used in data analysis and learning how to use modern libraries from the Python ecosystem to create efficient data pipelines. Starting with the essential statistical and data analysis fundamentals using Python, you’ll perform complex data analysis and modeling, data manipulation, data cleaning, and data visualization using easy-to-follow examples. You’ll then understand how to conduct time series analysis and signal processing using ARMA models. As you advance, you’ll get to grips with smart processing and data analytics using machine learning algorithms such as regression, classification, Principal Component Analysis (PCA), and clustering. In the concluding chapters, you’ll work on real-world examples to analyze textual and image data using natural language processing (NLP) and image analytics techniques, respectively. Finally, the book will demonstrate parallel computing using Dask. By the end of this data analysis book, you’ll be equipped with the skills you need to prepare data for analysis and create meaningful data visualizations for forecasting values from data.
Table of Contents (20 chapters)
Section 1: Foundation for Data Analysis
Section 2: Exploratory Data Analysis and Data Cleaning
Section 3: Deep Dive into Machine Learning
Section 4: NLP, Image Analytics, and Parallel Computing

Skewness and kurtosis

Skewness measures the symmetry of a distribution. It shows how much the distribution deviates from a normal distribution. Its values can be zero, positive, and negative. A zero value represents a perfectly normal shape of a distribution. Positive skewness is shown by the tails pointing toward the right—that is, outliers are skewed to the right and data stacked up on the left. Negative skewness is shown by the tails pointing toward the left—that is, outliers are skewed to the left and data stacked up on the right. Positive skewness occurs when the mean is greater than the median and the mode. Negative skewness occurs when the mean is less than the median and mode. Let's compute skewness in the following code block:

# skewness of communication_skill_score column


In the preceding code block, we have computed the skewness of the communication skill score column using the skew...