Building programs with Python
Python Style Guide
Learning Objectives
- Python coding conventions
This is taken from PEP-008: Python Style Guide. It is a semi-official guide to Python coding conventions.
We should stick to this unless we have hard data that proves something else is better.
Basic layout is as below:
- Indent blocks using four spaces
- Keep lines less than 80 characters long
- Separate functions with two blank lines
- Separate logical chunks of long functions with a single blank line
- Put comments on lines of their own, rather than to the right of code
Here are some basic python style rules listed in a table below:
| Rule | Good | Bad |
|---|---|---|
| No whitespace immediately inside parentheses or before the parenthesis starting indexing or slicing | max(candidates[sublist]) |
max( candidates[ sublist ] ) , max (candidates [sublist] ) |
| No whitespace immediately before comma or colon | if limit > 0: print minimum, limit |
if limit > 0 : print minimum , limit |
| Use space around arithmetic and in-place operators | x += 3 * 5 |
x+=3*5 |
| No spaces when specifying default parameter values | def integrate(func, start=0.0, interval=1.0) |
def integrate(func, start = 0.0, interval = 1.0) |
Never use names that are distinguished only by "l", "1", "0", or "O" |
tempo_long and tempo_init |
tempo_l and tempo_1 |
| Short lower-case names for modules (i.e., files) | geology |
Geology or geology_package |
| Upper case with underscores for constants | TOLERANCE or MAX_AREA |
Tolerance or MaxArea |
| Camel case for class names | SingleVariableIntegrator |
single_variable_integrator |
| Lowercase with underscores for function and method names | divide_region |
divRegion |
| and member variables | max_so_far |
maxSoFar |
Use is and is not when comparing to special values |
if current is not None: |
if current != None: |
Use isinstance when checking types |
if isinstance(current, Rock): |
if type(current) == Rock: |
<strong>Table 8.1: Basic Python Style Rules </strong>