If you’ve ever written Python code, there’s a good chance you’ve seen the error message “IndentationError: expected an indented block.” This error can be frustrating because it doesn’t always make it clear where the problem is. In this article, we’ll go over what causes this error and how to fix it.

What Causes the “IndentationError: expected an indented block” Error?

Indentation is a critical part of Python syntax. Unlike other programming languages, Python doesn’t use braces to group code. Instead, indentation is used to delineate the boundaries of code blocks. This means that you need to be careful about how you indent your code. If you don’t indent your code correctly, Python will raise an “IndentationError.”

The “IndentationError: expected an indented block” error occurs when Python expects a block of indented code but can’t find one. This can happen for several reasons:

1. Missing indentation: Python expects that a certain line of code should be indented. If this line is not indented, Python cannot determine where the block of code starts.

2. Incorrect indentation: If you don’t properly indent the code blocks in your script, Python will raise an indentation error when it can’t determine the correct structure of your code.

3. Mix of spaces and tabs: Python allows you to use either tabs or spaces for indentation, but you can’t mix them in the same block of code. Mixing tabs and spaces can lead to an indentation error.
How to Fix the “IndentationError: expected an indented block” Error

There are several common ways to fix the “IndentationError: expected an indented block” error.

1. Check indentation: First, check that each line of code has the correct level of indentation. In Python, this typically means using four spaces per indentation level. If you’re using tabs, make sure your editor is set to insert four spaces when you press the “Tab” key.

2. Remove mixed tabs and spaces: If you’re mixing tabs and spaces, the easiest way to fix this error is to remove all tabs and use spaces instead. Most editors can convert tabs to spaces automatically. In PyCharm, for example, you can go to the menu “Code” > “Reformat Code…” and select the “Spaces” option under “Tabs and Indents.”

3. Run an auto-indent tool: Some editors, like PyCharm and Sublime Text, have a feature that automatically indents your code. This can be useful if you’re unsure where your code blocks are supposed to start and end. Just select your code and use the auto-indent feature to fix any indentation errors.