An 'IndentationError' occurs when the indentation of your code is not consistent. Ensure that you're using the same type of indentation (spaces or tabs) throughout your script, and follow Python's indentation rules.

The 'IndentationError' is a common exception encountered in Python, primarily due to the language's strict rules regarding indentation. Unlike many programming languages that use braces or keywords to define blocks of code, Python relies on indentation to establish the structure of code. When the indentation is inconsistent—such as mixing tabs and spaces, or having an incorrect level of indentation—Python raises an IndentationError. To fix this error, start by reviewing your code for any irregularities in indentation. A best practice is to choose either spaces or tabs for indentation and stick with that choice consistently throughout your script. Most coding standards recommend using four spaces for indentation. If you're using an IDE or text editor, configure it to display whitespace characters, which can help you identify mixed indentation easily. Additionally, many code editors offer functionality to convert tabs to spaces, which can assist in correcting these errors quickly. By adhering to consistent indentation practices and configuring your development environment appropriately, you can effectively avoid and resolve IndentationErrors in your Python code.