Book Image

The Data Wrangling Workshop - Second Edition

By : Brian Lipp, Shubhadeep Roychowdhury, Dr. Tirthajyoti Sarkar
Book Image

The Data Wrangling Workshop - Second Edition

By: Brian Lipp, Shubhadeep Roychowdhury, Dr. Tirthajyoti Sarkar

Overview of this book

While a huge amount of data is readily available to us, it is not useful in its raw form. For data to be meaningful, it must be curated and refined. If you’re a beginner, then The Data Wrangling Workshop will help to break down the process for you. You’ll start with the basics and build your knowledge, progressing from the core aspects behind data wrangling, to using the most popular tools and techniques. This book starts by showing you how to work with data structures using Python. Through examples and activities, you’ll understand why you should stay away from traditional methods of data cleaning used in other languages and take advantage of the specialized pre-built routines in Python. Later, you’ll learn how to use the same Python backend to extract and transform data from an array of sources, including the internet, large database vaults, and Excel financial tables. To help you prepare for more challenging scenarios, the book teaches you how to handle missing or incorrect data, and reformat it based on the requirements from your downstream analytics tool. By the end of this book, you will have developed a solid understanding of how to perform data wrangling with Python, and learned several techniques and best practices to extract, clean, transform, and format your data efficiently, from a diverse array of sources.
Table of Contents (11 chapters)

Basic File Operations in Python

In the previous topic, we investigated a few advanced data structures and also learned neat and useful functional programming methods to manipulate them without side effects. In this topic, we will learn about a few OS-level functions in Python, such as working with files, but these could also include working with printers, and even the internet. We will concentrate mainly on file-related functions and learn how to open a file, read the data line by line or all at once, and finally, how to cleanly close the file we opened. The closing operation of a file should be done cautiously, which is ignored most of the time by developers. When handling file operations, we often run into very strange and hard-to-track-down bugs because a process opened a file and did not close it properly. We will apply a few of the techniques we have learned about to a file that we will read to practice our data wrangling skills further.

Exercise 2.08: File Operations