Python PEP 8 Code Formatter & Indentation Fixer
Normalize Python 3 indentation to 4-space PEP 8 standards, clean operator spacing, and format functions and classes 100% locally in your browser.
How do I use Python PEP 8 Code Formatter & Indentation Fixer?
Paste your Python 3 script, FastAPI endpoint, or data-science snippet into the Raw Input Code editor (Python mode and 4-Space PEP 8 indentation are pre-selected).
Adjust the Indent selector between 4 Spaces (official PEP 8 standard) or 2 Spaces if required by your project.
Review the live Formatted Output pane as nested blocks (`def`, `class`, `if/elif/else`, `for`, `try/except`) and operator spacing are automatically normalized.
Click 'Copy' to copy the PEP 8 formatted Python code or 'Download' to save it as `formatted_code.py`.
What features does Python PEP 8 Code Formatter & Indentation Fixer offer?
Defaults to official PEP 8 4-space indentation per level for Python 3
Automatically indents nested blocks following colon (`:`) block headers (`def`, `class`, `if`, `for`, `with`, `try`)
Normalizes spacing around assignment (`=`), comparison (`==`, `<=`, `>=`), and arithmetic operators
Collapses excessive blank lines while preserving logical function separation
Instant `.py` script file download and one-click clipboard copy
100% Client-Side execution — proprietary Python algorithms and API scripts never leave your browser
What are the core PEP 8 formatting rules for Python code?
Unlike brace-delimited languages (C, Java, TypeScript), Python uses lexical indentation level (`INDENT` and `DEDENT` tokens) to define executable code blocks. Mixing tabs and spaces or inconsistent indentation widths raises `IndentationError` or `TabError` at runtime.
Block Indent = 4 Spaces × Nesting Depth (After ':' in def, class, if, elif, else, for, while, with, try, except)Converts tabs to 4 spaces and aligns child statements after every colon-terminated compound statement header.
| PEP 8 Category | Standard Convention | Bad / Non-Compliant Example | PEP 8 Formatted Output |
|---|---|---|---|
| Indentation | 4 spaces per indentation level (no hard tabs) | 2 spaces or mixed `\t` tabs | 4 spaces (` return result`) |
| Line Length | 79 chars (code) / 80–100 chars modern | 200+ char horizontal lines | Wrapped cleanly within 80/100 chars |
| Operator Spacing | Single space around `=`, `==`, `+=`, `->` | `x=1+2` or `def fn(a:int)->bool:` | `x = 1 + 2` / `def fn(a: int) -> bool:` |
| Comma Spacing | Space after comma, none before | `[1,2,3]` or `fn(a , b)` | `[1, 2, 3]` and `fn(a, b)` |
How is Python PEP 8 Code Formatter & Indentation Fixer used in real-world workflows?
Normalizing Indentation on Snippets Copied from Docs or Chat
Quickly fix collapsed or 2-space indented Python functions copied from Slack, Stack Overflow, or LLM chats before pasting them into a PEP 8 codebase.
Cleaning Jupyter Notebook Cells for Production Scripts
Standardize messy exploratory Pandas and PyTorch notebook cells with consistent 4-space indentation and operator spacing prior to code review.
Frequently Asked Questions about Python PEP 8 Code Formatter & Indentation Fixer
Why does PEP 8 mandate 4 spaces instead of tabs in Python?
Python 3 strictly forbids mixing tabs and spaces for indentation (`TabError: inconsistent use of tabs and spaces in indentation`). Using 4 spaces per indentation level guarantees that code renders and executes identically across every editor, terminal, and Git diff viewer.
Does the Python formatter preserve strings when normalizing operator spacing?
Yes. String literals (such as URLs or SQL queries containing `=`, `+`, or `,`) are protected during operator spacing normalization so their contents are not altered.
Can I switch Python formatting from 4 spaces to 2 spaces?
Yes. While 4 Spaces (PEP 8) is selected by default when you open `/tools/python-formatter`, you can switch the Indent dropdown to 2 Spaces at any time.
Is my Python source code uploaded to a backend server?
No. The Python formatter runs 100% locally in your browser's JavaScript engine. Your proprietary scripts, SQL queries, and ML pipelines remain completely private.
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