Formatted Python will appear here...
Format Python code with proper indentation (4 spaces), spacing around operators, and consistent style following PEP 8 guidelines.
What is Python Formatter?
Python formatting follows PEP 8, the official Python style guide that establishes conventions for indentation, spacing, and code organization. Unlike brace-delimited languages where indentation is optional, Python uses indentation to define code blocks — making proper formatting not just a style preference but a correctness requirement. This tool normalizes Python code by enforcing 4-space indentation per PEP 8, adding consistent spacing around operators (=, +, -, ==), removing extra whitespace inside parentheses and brackets, and ensuring blank lines separate logical sections like function and class definitions. When you paste code that has been written with tabs, 2-space indentation, or inconsistent spacing, the formatter realigns everything to the standard convention. For production Python projects, tools like Black or autopep8 provide more comprehensive formatting with full AST parsing, but this tool is ideal for quick cleanup of snippets, debugging indentation errors, or preparing code for code review.
How to Use
- Paste Python code (messy or with inconsistent indentation)
- Click 'Format Python' to apply PEP 8 style
- Review 4-space indentation and operator spacing
- Copy formatted output for your project
Why Use This Tool?
Tips & Best Practices
- Python requires correct indentation - errors break code
- PEP 8 mandates 4-space indentation (not tabs)
- Check for mismatched indentation after format
- Use Black for production Python formatting
- Spacing around =, +, -, etc. improves readability
- Blank lines separate logical sections
Frequently Asked Questions
Why 4 spaces for Python?
PEP 8 Python style guide mandates 4 spaces per indentation level. Tabs are discouraged because they display differently across editors. Consistent 4-space indentation is Python convention and ensures code works correctly across all environments.
Can wrong indentation break Python?
Yes! Python uses indentation for code blocks. Wrong indentation causes IndentationError or changes program logic. Always verify indentation matches intended block structure after formatting, especially for nested if/for/while blocks.
What spacing changes are made?
Adds spaces around operators (=, +, -, *, /, ==, !=, <, >). Removes extra spaces inside parentheses and brackets. Normalizes comma spacing (a, b not a,b). Ensures blank lines between functions and logical sections.
What about docstrings and comments?
Comments and docstrings are preserved and indented correctly. Triple-quoted docstrings maintain their format. The formatter focuses on code structure, not comment content. Comments stay with their associated code blocks.
Should I use Black instead?
Black is the definitive Python formatter for production. It's more thorough and handles complex syntax perfectly. This tool is for quick formatting without setup. Use Black (pip install black) for automated project formatting.
How do I format entire Python projects?
Use Black CLI: black src/ formats all Python files in src directory. Or use autopep8 for PEP 8 compliance. This tool works best for individual snippets, debugging formatting issues, and quick cleanup without tool installation.
Is my Python code kept private?
Yes. Formatting runs entirely in your browser using client-side JavaScript. Your Python code is never sent to any server, never stored, and never logged. The tool works offline once the page is loaded.
When should I NOT use this formatter?
Avoid using this for Python code that uses type hints with complex generics, decorators with multi-line arguments, or f-strings with nested expressions — the pattern-based formatter may not handle these correctly. Also skip it if your project already uses Black or Ruff in its CI pipeline, since reformatting outside those tools can create conflicting style changes.
Real-world Examples
Fixing indentation errors in copied Python code
When copying Python code from documentation or Stack Overflow, indentation is often lost or mangled. Fix it before running to avoid IndentationError.
def process_data(items): result=[] for item in items: if item>0: result.append(item*2) else: result.append(item) return result
def process_data(items):
result = []
for item in items:
if item > 0:
result.append(item * 2)
else:
result.append(item)
return resultPreparing a Python script for code review
A script written quickly with inconsistent spacing and no blank line separation between functions needs cleanup before submitting for team review.
def load_config(path):with open(path) as f:return json.load(f)
def save_config(path,data):with open(path,'w') as f:json.dump(data,f,indent=2)
if __name__=="__main__":config=load_config('config.json')save_config('backup.json',config)def load_config(path):
with open(path) as f:
return json.load(f)
def save_config(path, data):
with open(path, 'w') as f:
json.dump(data, f, indent = 2)
if __name__ == "__main__":
config = load_config('config.json')
save_config('backup.json', config)