In my recent project there was a lot of data business logic, so I had to organize this code somehow. In this article I'll describe a few hints on how to it.
Mixins
Simple business logic functions should in models or managers. When there's a lot of them, the can be split in mixins.
# logic.py
class EventLogic(object):
def start(self):
if self.condition():
# ...
# models.py
class Event(models.Model, EventLogic):
name = models.CharField()
# ...Custom exceptions
For business logic errors you should declare custom exception classes. It's not fun to understand what this specific IntegrityError means.
Generic views
When all logic is in model and can throw, say, BusinessLogicException, we can write views like this:
from django.contrib import messages
def event_action(requets, event_id, action):
# event = get_object_or_404(...)
try:
getattr(event, action)(request.user)
except BusinessLogicException, e:
messages.warning(request, e.message)
return redirect(request.POST.get('next') or event)Subscribe for the news and updates
This article demonstrates how to use Python to automate yield calculations in decentralized finance (DeFi), focusing on the Renzo and Pendle platforms. It guides readers through estimating potential rewards based on factors like token prices, liquidity, and reward distribution rules, emphasizing the importance of regular data updates and informed decision-making in DeFi investments.
We reviewed the best payment gateways in 2020. Here’s our comparison of their features, advantages, and disadvantages.
In this article we will write a small library for pulling metadata and creating a preview for a site just like Slack does.
This article is aimed for beginners, who are trying to choose between Ruby on Rails and Django. Let’s see which is fastest and why.
I've created this small sprite to create css sprites. It glues images from directory directory into single file and generates corresponding css.
For local project settings, I use old trick with settings_local file:try:from settings_local import \*except ImportError:passSo in settings_local.py we can override variables from settings.py. I didn't know how to supplement them. For example how to add line to INSTALLED_APPS without copying whole list.Yesterday I finally understood that I can import settings from settings_local:# settings_local.pyfrom settings import \*INSTALLED_APPS += (# ...)