Error Encyclopedia

IndentationError: unexpected indent

Fix 'IndentationError: unexpected indent' in Python. Learn Python's indentation rules and how to fix spacing issues.

What Does This Error Mean?

The 'IndentationError: unexpected indent' error means Python encountered a line with indentation that does not match the expected block structure. Python uses indentation (whitespace at the start of lines) to define code blocks — unlike many languages that use braces or keywords.

Common Causes

1

Mixing tabs and spaces in the same file

2

Extra spaces before a line that should not be indented

3

Missing or extra indentation in a code block

4

Editor configured to use tabs while the project uses spaces (or vice versa)

5

Copying code from a web page that introduced inconsistent whitespace

6

Indentation level mismatch between an if/for/def and its body

How to Fix It

Use consistent indentation (4 spaces)

PEP 8 recommends 4 spaces per indentation level. Configure your editor to use spaces.

# ✅ Correct indentation with 4 spaces
def greet(name):
    if name:
        print(f"Hello, {name}")
    else:
        print("Hello, World")

# ❌ Mixed tabs and spaces
def greet(name):
	if name:
        print(f"Hello, {name}")  # Tab then spaces → Error

Reveal whitespace in your editor

Enable visible whitespace to see if tabs and spaces are mixed.

# VS Code: Ctrl+Shift+P → "Toggle Render Whitespace"
# Or add to settings.json:
"editor.renderWhitespace": "all"

# Find tabs in your file with Python
python -c "print(repr(open('file.py').read()))" | findstr \\t

Convert tabs to spaces

Use an automated tool to fix inconsistent indentation.

# Use autopep8 to fix indentation
pip install autopep8
autopep8 --in-place file.py

# Or use Python's own tabnanny for checking
python -m tabnanny file.py

# VS Code: Format Document (Shift+Alt+F)
# Or use "editor.formatOnSave": true

Before & After Examples

❌ Before
def calculate_total(items):
    total = 0
    for item in items:
        total += item.price
      return total  # ❌ Wrong indentation level
✅ After
def calculate_total(items):
    total = 0
    for item in items:
        total += item.price
    return total  # ✅ Correct indentation (back to for level)

Related Errors

Other common errors in this category:

ModuleNotFoundError: No module named

Fix 'ModuleNotFoundError: No module named' errors in Python. Learn to install missing packages, fix import paths, and manage virtual environments.

KeyError

Fix Python KeyError when accessing dictionary keys that do not exist. Learn to use .get(), setdefault(), and try-except safely.

ImportError: cannot import name

Fix 'ImportError: cannot import name' in Python. Learn why imports fail within modules and how to restructure your code to avoid circular dependencies.

AttributeError: 'NoneType' object has no attribute

Fix AttributeError: 'NoneType' object has no attribute errors in Python. Learn why functions return None and how to handle missing return values.

Frequently Asked Questions

Should I use tabs or spaces in Python?

PEP 8 (Python's style guide) recommends 4 spaces per indentation level. Most Python projects use spaces. Configure your editor to insert spaces when you press Tab.

How do I fix mixed tabs and spaces in an entire project?

Use `autopep8 --in-place --aggressive --aggressive **/*.py` or `black .` to auto-format your entire project. Use `python -m tabnanny *.py` to find files with inconsistent indentation.

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