sloria

The Best of the Best Practices (BOBP) Guide for Python

A "Best of the Best Practices" (BOBP) guide to developing in Python.

In General

Values

• "Build tools for others that you want to be built for you." - Kenneth Reitz
• "Simplicity is alway better than functionality." - Pieter Hintjens

sloria

# -*- coding: utf-8 -*-
'''recorder.py
Provides WAV recording functionality via two approaches:

Blocking mode (record for a set duration):
>>> rec = Recorder(channels=2)
>>> with rec.open('blocking.wav', 'wb') as recfile:
...     recfile.record(duration=5.0)

Non-blocking mode (start and stop recording):

sloria

# Even better

def lazy_property(fn):
    '''Decorator that makes a property lazy-evaluated.
    '''
    attr_name = '_lazy_' + fn.__name__

    @property
    def _lazy_property(self):
        if not hasattr(self, attr_name):

sloria

{"lastUpload":"2021-08-17T14:10:13.842Z","extensionVersion":"v3.4.3"}

sloria

class Point:
    def __init__(self, x, y):
        self.x, self.y = x, y

# Sometimes need more flexibility --> use properties

class Point:
    def __init__(self, x, y):
        self._x, self._y = x, y

sloria

# Bad
# Can't change type of collection
#     e.g. can't change employees from a list to a set
class Department:
    def __init__(self, *employees):
        self.employees = employees

for employee in department.employees:
    ...
    

sloria

obj == obj2
obj1 is obj2

class Book:
    ...
    def __eq__(self, other):
        if not isinstance(other, self.__class__):
            return NotImplemented
        return (self.author == other.author and 
                self.title == other.title)

sloria

class Book:
    ...
    def __hash__(self):
        return hash(self.author) ^ hash(self.other)

sloria

class Book:
    ...
    def __lt__(self, other):
        return (self.author, self.title) < (other.author, other.title)

sloria

class Config:
    def __init__(self, **entries):
        self.entries = entries

    def __add__(self, other):
        entries = (self.entries.items() + 
                    other.entries.items())
        return Config(**entries)
default_config = Config(color=False, port=8080)
config = default_config + Config(color=True)