A Beginner’s Guide to Python Exit Codes: a blog around the exit codes in python.
Python is one of the most popular programming languages that developers use to build different kinds of applications. It was first released in 1991 and has since become an integral part of the software development world. One of the main reasons why developers love it so much is because of how easy Python makes it to develop code, write scripts, and build applications.
But like any other programming language, Python has its own set of rules and guidelines regarding how you should build your codebase and what kind of style you should follow when coding in Python. This is important because it makes it easy for other developers to read your code and understand what is going on!
One such guideline is naming conventions — where specific words have particular meanings or functions within our code base that help us understand what they mean when looking at them without having to guess! In this article we’ll explore some examples where these conventions exist and why they’re useful!
Exit codes in Python are a somewhat untapped and misunderstood subject. To understand what they are and how they work, we’re going to dive into the code, analyze and explain them.
If you want to learn more about exit codes and how they affect your programs, this blog is for you!
But before we start with it, let’s summarize what exit codes are: What Are Exit Codes?
Exit codes are numeric values that the shell commands return. The value of the code indicates if the execution was successful or not. If a command finishes with a 0 exit code, it means that everything worked fine. If it finishes with a non-zero exit code, it means some error occurred during the execution of the command.
The exit codes are mostly used for automated scripts and batch files to tell whether the script was successfully executed or not. They also help you to identify which command is causing problems and where specifically you should focus on debugging.
In this article, we are going to discuss Exit Codes in Python which is a fundamental topic for beginners. We will see what the exit codes mean, how to check the exit code of a particular command and also how to set a particular exit code on your own.
Exit Code :
In general terms, an exit code is a return value that is given by executing a program after it terminates or fails. Every linux command executed from the bash shell has an exit status. If the program executes successfully, then it returns 0; if there is a failure, then it returns another number. It is possible to check the exit status of a process using its pid as shown below:
import os
pid = os.getpid()
Exit codes are a number between 0 and 255, which is returned by any Unix command when it returns control to its parent process. Whenever a program exits, it returns an exit code. Generally, an exit code of “0” indicates that the program ended successfully, and a non-zero exit code means that the program didn’t work as intended.
The Python documentation for sys.exit() says:
Exits the interpreter by raising SystemExit(status). If the status is omitted or None, it defaults to zero (i.e., success). If the status is an integer, it will be used as the system exit status. If it is another kind of object, it will be printed and the system exit status will be one (i.e., failure).
In this post, I’m going to tell you what an exit code is and show you how to use them on your computer. I’m also going to show you how to use exit codes in your Python scripts.
Before we look at exit codes, let’s discuss commands for a second. When we use a command line interface (CLI), we type commands that the computer will run. The actions of these commands are executed immediately when they are entered into the CLI.
Let’s take a look at some commands:
$ ls -la
total 16
drwxr-xr-x 4 michaela staff 128 May 21 10:49 .
drwxr-xr-x+ 28 michaela staff 896 May 21 10:48 ..
-rw-r–r–@ 1 michaela staff 628 May 21 10:49 .DS_Store
drwxr-xr-x@ 13 michaela staff 416 May 21 10:49 .git
I used to think that the most important thing in my programming career was to be able to write code that can execute smoothly. But one of the greatest things I learned over the years is that the code must exit at some point, and it should do it gracefully.
When we write a program, whether it’s a command line tool or a library, we want our code to be able to handle different kinds of errors and handle them accordingly. This is very important as handling errors is what separates good programmers from bad ones.
For example, if you are writing an application which uses a database, you want it to make sure that the database connection is closed once the work is done. You also want to make sure that all files you opened are properly closed and your resources are released when the program exits.
To achieve this, we need our code to know why it’s exiting so it can take necessary actions before exiting. This means that our code must know what’s happening inside.
Every Linux or Unix command executed by the shell script or user, has an exit status. The exit status is an integer number. 0 exit status means the command was successful without any errors. A non-zero (1-255 values) exit status means command was a failure. This tutorial will help you to get the exit status of a command in Python.
The following example creates a simple script which will print “Hello World” message and then it exits with exit code 1: