Python Coding Style Guidelines (Applicable to Django)

This document outlines a complete set of Python coding style rules that improve readability and maintainability, and are also suitable for Django projects.

Indentation : Use four spaces per indentation level.

Line length : Keep lines under 80 characters (max 120 in special cases). This aids side‑by‑side diffs, console viewing, and highlights design issues.

Quotes : Use single quotes for machine identifiers, double quotes for natural language strings, triple double quotes for docstrings, and raw strings for regular expressions.

Blank lines : Separate module‑level functions and class definitions with two blank lines; separate class methods with one blank line. Multiple blank lines can separate logical groups of functions.

Encoding : Files should be UTF‑8 encoded; a coding header is optional for Python 3.

Import statements : Write each import on its own line, place imports after module docstrings, use absolute imports, order groups with a blank line between them, and prefer explicit imports.

import os import sys import msgpack import zmq import foo

Spaces : Surround binary operators with a single space, avoid spaces inside parentheses or brackets, and do not add extra spaces around default‑value equals signs.

# Correct spacing i = i + 1 submitted += 1 x = x * 2 - 1 hypot2 = x * x + y * y c = (a + b) * (a - b)

Line breaks : For long statements, break after commas, align subsequent lines with the opening parenthesis, or use a backslash for continuation. Avoid multiple statements on one line.

foo = long_function_name(var_one, var_two, var_three, var_four)

Comments : Block comments start with # followed by a space and are separated by blank lines; line comments should be preceded by at least two spaces from the code.

# Block comment # Another block comment

Docstrings : Follow PEP 257 – every public module, class, function, and method should have a docstring, and the closing triple quotes should be on a line by themselves unless the docstring is a single line.

"""Return a foobar Optional plotz says to frobnicate the bizbaz first. """ """Oneline docstring"""

Naming conventions : Avoid ambiguous single‑character names, use lowercase with underscores for modules and functions, CamelCase for classes, uppercase with underscores for constants, and add a trailing underscore to avoid clashes with Python keywords.

These guidelines collectively form a practical style guide for writing clean, consistent Python code.