Book Image

Python Data Analysis - Second Edition

By : Ivan Idris
Book Image

Python Data Analysis - Second Edition

By: Ivan Idris

Overview of this book

Data analysis techniques generate useful insights from small and large volumes of data. Python, with its strong set of libraries, has become a popular platform to conduct various data analysis and predictive modeling tasks. With this book, you will learn how to process and manipulate data with Python for complex analysis and modeling. We learn data manipulations such as aggregating, concatenating, appending, cleaning, and handling missing values, with NumPy and Pandas. The book covers how to store and retrieve data from various data sources such as SQL and NoSQL, CSV fies, and HDF5. We learn how to visualize data using visualization libraries, along with advanced topics such as signal processing, time series, textual data analysis, machine learning, and social media analysis. The book covers a plethora of Python modules, such as matplotlib, statsmodels, scikit-learn, and NLTK. It also covers using Python with external environments such as R, Fortran, C/C++, and Boost libraries.
Table of Contents (22 chapters)
Python Data Analysis - Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface
Key Concepts
Online Resources

Data aggregation with Pandas DataFrames


Data aggregation is a term used in the field of relational databases. In a database query, we can group data by the value in a column or columns. We can then perform various operations on each of these groups. The Pandas DataFrame has similar capabilities. We will generate data held in a Python dict and then use this data to create a Pandas DataFrame. We will then practice the Pandas aggregation features:

  1. Seed the NumPy random generator to make sure that the generated data will not differ between repeated program runs. The data will have four columns:

    • Weather (a string)

    • Food (also a string)

    • Price (a random float)

    • Number (a random integer between one and nine)

    The use case is that we have the results of some sort of consumer-purchase research, combined with weather and market pricing, where we calculate the average of prices and keep a track of the sample size and parameters:

                import pandas as pd
                from numpy.random import seed...