src/experiments/base.py

   1 import hashlib
   2 from django.conf import settings
   3
   4
   5 class Experiment:
   6     slug = None
   7     name = 'experiment'
   8     explicit = False
   9     size = 0
  10     switchable = True
  11
  12     def qualify(self, request):
  13         return True
  14
  15     def __init__(self, request):
  16         self.value, self.manual = self.get_value(request)
  17
  18     def override(self, value):
  19         self.value = value
  20         self.manual = False
  21
  22     def get_value(self, request):
  23         overrides = getattr(settings, 'EXPERIMENTS_OVERRIDES', {})
  24         slug = self.slug
  25         if slug in overrides:
  26             return overrides[slug], False
  27
  28         if self.qualify(request) is False:
  29             return None, False
  30
  31         if self.switchable or request.user.is_staff:
  32             cookie_value = request.COOKIES.get(f'EXPERIMENT_{slug}')
  33             if cookie_value is not None:
  34                 if cookie_value == 'on':
  35                     return True, True
  36                 elif cookie_value == 'off':
  37                     return False, True
  38
  39         number = int(
  40             hashlib.md5(
  41                 (slug + request.META['REMOTE_ADDR']).encode('utf-8')
  42             ).hexdigest(),
  43             16
  44         ) % 10e6 / 10e6
  45         return number < self.size, False