Google - Using Python to Interact with the Operating System

INSTRUCTORS

Instructors: Google

By the end of this course, you’ll be able to manipulate files and processes on your computer’s operating system. You’ll also have learned about regular expressions – a very powerful tool for processing text files – and you’ll get practice using the Linux command line on a virtual machine. And, this might feel like a stretch right now, but you’ll also write a program that processes a bunch of errors in an actual log file and then generates a summary file. That’s a super useful skill for IT Specialists to know.

Syllabus

Managing Files with Python

• In this module, you’ll learn about reading and writing to files and the commands that will enable you to do this. We’ll learn the importance of managing files and how we can navigate through different directories. We’ll understand how to work with files and how there is a layer of abstraction between Python and the operating system. Finally, we’ll dive into learning about CSV files and how to best utilize them.

Regular Expressions

• In this module, you’ll learn about what a regular expression is and why you would use one. We’ll dive into the basics of regular expressions and give examples of wildcards, repetition qualifiers, escapare characters, and more. Next up, we’ll explore advanced regular expressions and deep dive on repetition qualifiers. You’ll tackle new exercises like capturing groups and extracting PIDs using regexes. Finally, we’ll provide a cheat sheet to serve as your go-to guide for regular expressions.

Managing Data and Processes

• In this module, we’ll learn about reading and writing to data files based on an interaction with the user. Along the way, we’ll dive into standard streams, environment variables, and command line arguments. Next, we’ll jump into Python subprocesses, including system commands and how they can be used. We’ll review how to obtain output from a system command, and dive into subprocess management, including how to check exit values and manipulate the normal versus error exit values. Finally, we’ll rundown processing log files, and will cover what a log file is, how to filter log files using regular expressions, and how to understand the output captured from log files.

Testing in Python

• In this module, you’ll learn how to create tests in Python. We’ll cover what testing is all about and dive into the differences between manual versus automated testing. Next, we’ll explore what unit tests are intended to do and how to write them. Then, we’ll learn about other test concepts like black box versus white box tests and how test-driven development can frame how you design and write your code. Finally, you’ll learn about errors and exceptions, and how to combat them.

Bash Scripting

• In this module, you’ll be exposed to what the Linux OS has to offer and you’ll learn about Bash scripting. We’ll go over basic Linux commands and explore the many processes Linux has to offer, including a key concept called redirection. We’ll then deep dive into creating bash scripts using variables and globs. Finally, we’ll learn about advanced bash concepts and develop an understanding of when to use bash versus Python.

Final Project

• In this module, you’ll put everything you’ve learned so far into action! You’ll apply your scripting knowledge to tackle a challenging final project: writing a script that scans for a specific error in the log files.

You’ll create a problem statement to understand the challenge, conduct some research to see what options are available, then begin planning how you intend to solve the problem. Lastly, you’ll write the code to implement your solution!