Book Image

Hands-On Data Analysis with Pandas - Second Edition

By : Stefanie Molin
Book Image

Hands-On Data Analysis with Pandas - Second Edition

By: Stefanie Molin

Overview of this book

Extracting valuable business insights is no longer a ‘nice-to-have’, but an essential skill for anyone who handles data in their enterprise. Hands-On Data Analysis with Pandas is here to help beginners and those who are migrating their skills into data science get up to speed in no time. This book will show you how to analyze your data, get started with machine learning, and work effectively with the Python libraries often used for data science, such as pandas, NumPy, matplotlib, seaborn, and scikit-learn. Using real-world datasets, you will learn how to use the pandas library to perform data wrangling to reshape, clean, and aggregate your data. Then, you will learn how to conduct exploratory data analysis by calculating summary statistics and visualizing the data to find patterns. In the concluding chapters, you will explore some applications of anomaly detection, regression, clustering, and classification using scikit-learn to make predictions based on past data. This updated edition will equip you with the skills you need to use pandas 1.x to efficiently perform various data manipulation tasks, reliably reproduce analyses, and visualize your data for effective decision making – valuable knowledge that can be applied across multiple domains.
Table of Contents (21 chapters)
Section 1: Getting Started with Pandas
Section 2: Using Pandas for Data Analysis
Section 3: Applications – Real-World Analyses Using Pandas
Section 4: Introduction to Machine Learning with Scikit-Learn
Section 5: Additional Resources

Aggregating data

We already got a sneak peek at aggregation when we discussed window calculations and pipes in the previous section. Here, we will focus on summarizing the dataframe through aggregation, which will change the shape of our dataframe (often through row reduction). We also saw how easy it is to take advantage of vectorized NumPy functions on pandas data structures, especially to perform aggregations. This is what NumPy does best: it performs computationally efficient mathematical operations on numeric arrays.

NumPy pairs well with aggregating dataframes since it gives us an easy way to summarize data with different pre-written functions; often, when aggregating, we just need the NumPy function, since most of what we would want to write ourselves has previously been built. We have already seen some NumPy functions commonly used for aggregations, such as np.sum(), np.mean(), np.min(), and np.max(); however, we aren't limited to numeric operations—we can use...