dchuvardynskyi

{# load custom tags #}
{% load custom_tags %}

...
{# use our custom tags #}
<p>{{ order.total_cost|money_display }}</p>

...

dchuvardynskyi

from django import template

from utils import money_display

register = template.Library()

@register.filter()
def money_display(value):
    return money_display(value)

dchuvardynskyi

from django.dispatch import receiver, Signal
from tasks import notify_advisor
from order.models import Order

# create custom signal by property field
# instance field is reserved by signal
property_changed = Signal(providing_args=["instance", "property"])

@receiver(property_changed, sender=Order)
def notify_advisor(sender, instance, property, **kwargs):

dchuvardynskyi

from celery import Celery

celery_app = Celery()

@celery_app.task
def daily_notificator():
    # notifications logic here :)

    
# schedule task    

dchuvardynskyi

from views import SomeView

view = SomeView()
view.get_order()
# cache_property save our function call to magic object dict attribute
# location of value view.__dict__['get_order']

# we can get access to this cache, wtih magic method __dict__
view.__dict__['get_order']
# >>> our order

dchuvardynskyi

from cached_property import cached_property


class SomeView:
    ...

    @cached_property
    def get_order():
      order = get_object_or_404(Order, pk=self.self.kwargs['order_id'])
      return order

dchuvardynskyi

from decorators import count_calls

@count_calls
def say_whee():
    print("Whee!")
    
# >>> say_whee()
# Call 1 of 'say_whee'
# Whee!
# 

dchuvardynskyi

import functools


def count_calls(func):
    @functools.wraps(func)
    def wrapper_count_calls(*args, **kwargs):
        wrapper_count_calls.num_calls += 1
        print(f"Call {wrapper_count_calls.num_calls} of {func.__name__!r}")
        return func(*args, **kwargs)
    wrapper_count_calls.num_calls = 0

dchuvardynskyi

from decorators import timer


@timer
def waste_some_time(num_times):
    for _ in range(num_times):
        sum([i**2 for i in range(10000)])
        
# >>> waste_some_time(1)
# Finished 'waste_some_time' in 0.0010 secs

dchuvardynskyi

import functools
import time

def timer(func):
    """Print the runtime of the decorated function"""
    @functools.wraps(func)
    def wrapper_timer(*args, **kwargs):
        start_time = time.perf_counter()    # before main function call
        value = func(*args, **kwargs)
        end_time = time.perf_counter()      # after main function call