Adventures in Machine Learning

Python Programming: Solving Indentation Errors and Consistency Issues

Python is a popular programming language that is often used for a wide variety of applications, from web development to data analysis. With its simple syntax and ease of use, Python is a great choice for both beginners and experienced programmers alike.

However, there are some common issues that can arise when working with Python, particularly when it comes to indentation and formatting. In this article, we will explore two related topics in Python programming: the error that can occur when mixing tabs and spaces in indentation, and the recommendation to use spaces over tabs when it comes to indentation.

We will discuss what these issues are, why they matter, and how to deal with them in your Python code. Python Error: Mixing Tabs and Spaces in Indentation

Have you ever encountered a TabError while working with Python?

This error occurs when tabs and spaces are used inconsistently within the same block of code. It can be frustrating to encounter, as it can often take some time to track down the source of the problem.

But why does this error occur, and how can it be avoided? The root cause of a TabError is the inconsistent use of tabs and spaces in indentation.

In Python, whitespace is significant, and code blocks are defined by their indentation level. If you mix tabs and spaces within the same block of code, Python will get confused and throw a TabError.

So how can you avoid this error? The easiest solution is to stick to one type of indentation throughout your code: either use only tabs or only spaces.

This will ensure that your code is consistent and easy to read, and will avoid any issues with mixing tabs and spaces. A useful tool for detecting mixing tabs and spaces is tabnanny.

This module can be run on your Python code and will highlight any locations where you have mixed tabs and spaces. Once you have identified these areas, you can convert them all to either tabs or spaces using your preferred text editor.

Many modern editors, such as VS Code,

Sublime Text, and

Vim, have built-in features to make this process easier. It is worth noting that using spaces instead of tabs is the recommended approach in Python, as we will discuss further in the next section.

Python Style Guide (PEP 8): Using Spaces over Tabs

Python has its own style guide, known as PEP 8, which covers various aspects of Python programming including naming conventions, documentation, and formatting. When it comes to indentation, PEP 8 recommends using spaces instead of tabs.

The reasoning behind this recommendation is that spaces are more consistent in their display across different editors and platforms. Tabs can have different widths depending on the settings of the editor being used, which can lead to inconsistent formatting and potentially even the same kind of TabError we discussed earlier.

PEP 8 recommends using four space characters for each indentation level. This is a common convention in the Python community and makes it easy to read and understand code.

It is also important to maintain consistent indentation throughout your code. This means using the same number of spaces for each indentation level, and avoiding mixing tabs and spaces within the same block of code.


In conclusion, consistent indentation is crucial when it comes to writing readable and maintainable Python code. Mixing tabs and spaces in indentation can lead to TabErrors and other issues that can be frustrating to diagnose and fix.

By sticking to either tabs or spaces and maintaining consistent indentation, you can avoid these issues and make your code easier to read and understand. The Python style guide, PEP 8, recommends using spaces over tabs for indentation, with four space characters for each indentation level.

This convention is widely used in the Python community and helps to ensure consistency and readability across different editors and platforms. Whether you are new to Python programming or an experienced developer, understanding these concepts will help you write better, more readable code.

So next time you start writing Python code, remember to stick to one kind of indentation and use spaces instead of tabs!

Python programming requires code consistency to avoid confusion and errors that can affect the final product of your code. Despite best efforts to maintain such consistency, issues can still arise, particularly when working on different code editors.

In this article, we provide tips for dealing with inconsistent indentation in different code editors.

Making Whitespaces Visible in Code Editors

Missing or mixed whitespaces can lead to indentation issues which, in turn can cause big problems in your code. To ensure the consistency of your code in different code editors, you should enable indicators or provide feedback about the exact positioning of whitespaces in your code.

This feature can be found in most code editors and allows you to customize the settings to your preference. Once enabled, your code editor will display a dotted line in place of tabs, allowing you to better track and manage your codes indentation.

Automatically Convert Unwanted Tabs into Spaces

While software engineers know to use spaces instead of tabs, older codebases and lines of code may require you to convert tabs into spaces. Thankfully, most code editors provide this option in their settings.

The Convert Indentation to Spaces option will perform the necessary conversion automatically, so you dont have to painstakingly replace every tab with the right amount of spaces manually. Similarly, the Convert Indentation to Tabs command can be used to turn spaces into tabs, again, saving you the effort of performing the task manually.


Vim users, you can use the :retab command to convert all tabs to spaces or vice versa in your code. Simply type :retab in

Vims command mode, and it will convert all spaces to tabs or vice versa, depending on the current settings.

Specific Instructions for Three Popular Code Editors

VS Code

To indent using spaces in Visual Studio Code:

1. Open your file in VS Code and navigate to the bottom-right corner of the screen to select the Spaces option.

2. Click on the Space/TAB Code Lens that appears over the spaces option and select the number of spaces required for indentation.

3. Code Lens will become hidden, and you can now indent using the spaces key instead of the tab key.

Sublime Text

To set listchars in

Sublime Text, follow these steps:

1. Open your file in

Sublime Text and navigate to the Preferences menu.

2. Choose Settings – Syntax Specific to edit your preferences for your file type.

3. Add “draw_white_space”: “all”, to the user preferences on the right side of the editor window.

4. Add “set listchars=tab: ,trail:” to the User Settings Preferences.


To set listchars in

Vim, follow these simple steps:

1. Open your file in

Vim and type :set list to display the list of tab and space characters in your file.

2. The default characters are – for spaces and ^I for tabs.

3. Change these settings by typing :set listchars+=tab:,trail: to use arrows, boxes, and dots, respectively, to indicate spaces and tabs.



As an open-source contributor and software engineer, I know firsthand the challenges of maintaining consistent code across various editors. The tips provided in this article have helped me overcome some of those challenges, and I hope they will be helpful to you too.

By making whitespaces visible and using automated conversion tools, your code will be clearer and easier to manage, even when switching between editors. Following the specific instructions for VS Code,

Sublime Text, and

Vim will help you maintain consistent and readable indentation in your code.

Thank you for reading! If you found this guide helpful, feel free to tweet me your thoughts or ways I can continue to improve. In conclusion, maintaining consistent indentation in Python is crucial for writing readable, maintainable code.

Mixing tabs and spaces can lead to errors, which can be hard to track down and resolve. By using spaces over tabs and setting them to four spaces per indentation level, your code will be easy to read and understand.

You can also enable indicators or feedback for whitespaces in your code editor and use automatic conversion tools to avoid inconsistencies. Remember to follow specific instructions in popular code editors like VS Code,

Sublime Text, and

Vim to maintain consistent indentation.

By following these tips, you can ensure your code is of high quality and easy to maintain.

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