TabError: inconsistent use of tabs and spaces in indentation — how to fix

TabError: inconsistent use of tabs and spaces in indentation

Quick fix: Convert all tabs to 4 spaces: in VS Code use Ctrl+Shift+P → Convert Indentation to Spaces; on the command line expand -t 4 file.py > tmp && mv tmp file.py.

What it means

Python 3 refuses to guess how wide a tab is. If one block mixes tabs and spaces, it raises TabError instead of running code that might mean something different from what it looks like.

Fix

Use spaces only (PEP 8 recommends 4 per level).

VS Code: Ctrl+Shift+P → Convert Indentation to Spaces, and set "editor.insertSpaces": true.

PyCharm: Edit → Convert Indents → To Spaces.

Vim: :set expandtab then :retab.

Command line:

expand -t 4 script.py > script_fixed.py && mv script_fixed.py script.py

Find the tabs

grep -nP '\t' script.py

Prevent it

Add an .editorconfig file to your project:

[*.py]
indent_style = space
indent_size = 4

Formatters like black or ruff format also normalise indentation every time you save.

Last updated 2026-10-27.