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Mastering Debugging in Python: Tips and Techniques

Titus Kiplagat's photo
Titus Kiplagat
·

3 min read

Table of contents

Introduction

Debugging is an essential skill for every programmer. It helps identify and resolve errors and issues in code, ensuring the smooth execution of programs. In this blog post, we'll dive into the world of debugging in Python and explore various techniques to effectively debug your code. So, let's embark on this debugging journey and become master debuggers!

Header: Unveiling the Secrets of Debugging in Python

Common Error: Syntax Error in Ubuntu

While working on a Python script in Ubuntu, you might encounter an error similar to the following:

./bubble.py: line 2: syntax error near unexpected token `('
./bubble.py: line 2: `def bubble_sort(num):'

This error occurs when trying to execute a Python script using the ./ notation, followed by the script name. The error message suggests a syntax issue near the opening parenthesis in line 2.

Solution: Using python3 to Execute Python Scripts

To resolve this error, instead of using ./ to execute the Python script, use the python3 command followed by the script name. Here's the corrected command:

python3 bubble.py

Using python3 explicitly ensures that the script is interpreted with the correct Python version and resolves any syntax errors caused by incompatible versions.

Debugging Techniques: Mastering the Art of Debugging in Python

1. Print Statements

One of the simplest and most effective debugging techniques is using print statements to display variable values and execution flow. Place print statements strategically throughout your code to track the value of variables at different stages. This helps identify incorrect or unexpected values and locate the source of errors.

def bubble_sort(num): print("Before sorting:", num) # Bubble sort logic print("After sorting:", num)

def bubble_sort(num):
    print("Before sorting:", num)
    # Bubble sort logic
    print("After sorting:", num)

# Example usage
numbers = [5, 2, 8, 12, 3]
bubble_sort(numbers)

2. Using pdb for Interactive Debugging

Python provides a built-in debugger module called pdb, which allows for interactive debugging. You can set breakpoints, step through code line by line, examine variable values, and execute commands during debugging.

import pdb

def bubble_sort(num):
    # Bubble sort logic
    pdb.set_trace()  # Set a breakpoint

# Example usage
numbers = [5, 2, 8, 12, 3]
bubble_sort(numbers)

When the script encounters the pdb.set_trace() statement, it pauses execution and opens an interactive debugger. From there, you can inspect variables, execute code, and navigate through the program using various commands.

3. Using IDEs with Debugging Support

Integrated Development Environments (IDEs) like PyCharm, Visual Studio Code, and PyDev offer powerful debugging features. These IDEs provide graphical interfaces for setting breakpoints, stepping through code, and analyzing variables in real-time. They also offer additional features like watches, call stacks, and interactive consoles to enhance the debugging experience.

Conclusion

In this blog post, we explored the world of debugging in Python and learned valuable techniques to identify and fix errors in our code. We discussed common syntax errors when executing Python scripts in Ubuntu and provided a solution using the python3 command.

We also delved into two powerful debugging techniques: using print statements to track variable values and execution flow, and leveraging the pdb module for interactive debugging. Furthermore, we mentioned the benefits of using IDEs with advanced debugging features.

By mastering these debugging techniques, you'll be well-equipped to tackle any issues that arise during development and ensure your Python code runs

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