Popular and Easy Debugging Techniques for Python Applications
Introduction
Every programming language provides debugging as a standard feature. Debugging’s primary goal is to make the code error-free so that it can function efficiently and deliver services to clients.
Debugging developers find and fix errors that harm the program’s efficiency and find and address issues that may jeopardize the program’s efficiency. These tasks aid in finding the bug’s root cause, allowing the problem to be resolved quickly and effectively.
In this article, we will look at some simple Python debugging techniques.
Top Debugging Approaches in Python
1. Exception Handling
Exceptional occurrences, often known as “exceptions”, occur when programmers run the program. As a result, program execution comes to a standstill, and the usual flow of the program comes into question. Developers employ exceptional handling strategies to debug their programs and prevent this anomalous behavior.
To handle exceptions efficiently in Python, we must try to capture block functions. You might be unable to handle some exceptions using the try and catch block if it is being incorrectly implemented. Let’s understand this with a basic program.
This is a basic division program in which I divide a number by zero. As we all know, dividing a number by zero results in infinity, which the computer or program cannot handle.
As a result, it threw an error, revealing a lot of information about the application and its location.
How to Handle Exceptions:
When an error happens in Python, it is represented as an exception, or a developer can raise an exception using the raise keyword.
To deal with it, programmers can use the try and except keywords. The code that generates an exception is provided by the developer inside the try block. Developers should indicate the error that needs to be generated if the exception occurs in the except block.
Note: There can be numerous except in a try block.
So, when the program runs and an error occurs, the error will be handled by the except block, which will display a simple error message.
2. Print/Check
In the basic debugging approach, developers publish the values of variables and check if they are being assigned the expected value or not. After printing the value, if the developer notices that the value is incorrect, he can examine the program’s logic or how the variable is being utilized to identify the issue that is causing the trash value to be set to the variable.
Once we’ve verified everything, we can delete the print statement from the program.
Example: We can check the value of the “C” variable.
The output is that as on printing, we come to know that the problem resides in line 3.
Note: Print statements make debugging easy.
3. Assert/Check
In Python, we have an inbuilt debugging utility — “Assert” — which generates an “AssertionError” if the statement is “False”. It has “-0”. If we pass an assert statement, it will close all assert statements within the Python program when the interpreter is being started. To utilize the assert statement, we need some specific experience. A novice programmer can make mistakes when using it.
So, if the conditions of the assert statement are true, then the program will keep running, and if the conditions become false, it will stop the execution of the program.
4. Use of Logging Module
In Python, there is a package named “Logging” that provides additional debugging options. When it comes to debugging Python code, it gives you a lot of options. It can debug, record, and monitor the execution of a Python application. In addition, it has the ability to save the log to a file rather than printing it to the terminal.
As a result, developers can navigate according to their facility. You can also print the output of the application for developers to use it in the future.
Example: We can see that we are utilizing the “warning” function for logging reasons in the program below.
As I run the program, I got:
5. pdb
pdb is Python’s built-in debugging tool. It can be used from the command line, within an interpreter, or within a program to assist the developer run the program in a single-step mode. Developers can use the pdb debugger to set breakpoints and inspect the source code.
Now, if we use pdb to run the Python program in the terminal, we can use –m as an argument.
Here, test4 is the name of the program.
You can see where the cursor is, and it simply runs the first line. To run the next line of code, the developer must supply instructions such as pressing enter to continue debugging or typing n to run the next line of code.
As a result, the developer will be able to see where the program is stuck or where the issue is occurring.
The full output of the program:
It has one more option, “p”, which requires the user to pass a variable name to determine whether the value is correct or not. If a user wants to set a breakpoint, he can use the pdb.set_trace() function.
6) Integrated Development Environment/IDE
Python, a computer language, is now acquiring a lot of popularity among developers. As a result, there are many IDEs available in the market. One of the key advantages of these IDEs is that their developers simply set breakpoints and execute code in a single step. Generally, they can also be utilized for remote debugging. Multiple IDEs are available such as:
Pycharm: It comes in a community version with a number of features. It can be accessed through the command line, it connects to databases easily, and it can construct a virtual environment. As a result, it increases developer productivity.
Visual Studio Code: You need to install the Microsoft Python plugins to use it. This add-on turns VS (Virtual Studio) Code into a Python editor, allowing you to work with any Python interpreter. It offers a number of features, including autocomplete, intelligence, linting, debugging, and unit testing.
Eclipse: After installing the “Pydev” plugin, Eclipse can work as a Python IDE. It can also support “Jython” and “IronPython”.
Conclusion
Developers have a variety of options for debugging. It is up to him to decide which one they want to utilize based on their requirements. Debugging is a fundamental requirement for any programmer who wants to be a productive developer.
There are a couple of approaches that can be used for debugging, and the developer has to decide which specific approach is best suited for their application.
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