devscripts/lazy_load_template.py

   1 # coding: utf-8
   2 import re
   3
   4 from ..utils import bug_reports_message, write_string
   5
   6
   7 class LazyLoadMetaClass(type):
   8     def __getattr__(cls, name):
   9         if '_real_class' not in cls.__dict__:
  10             write_string(
  11                 f'WARNING: Falling back to normal extractor since lazy extractor '
  12                 f'{cls.__name__} does not have attribute {name}{bug_reports_message()}')
  13         return getattr(cls._get_real_class(), name)
  14
  15
  16 class LazyLoadExtractor(metaclass=LazyLoadMetaClass):
  17     _module = None
  18     _WORKING = True
  19
  20     @classmethod
  21     def _get_real_class(cls):
  22         if '_real_class' not in cls.__dict__:
  23             mod = __import__(cls._module, fromlist=(cls.__name__,))
  24             cls._real_class = getattr(mod, cls.__name__)
  25         return cls._real_class
  26
  27     def __new__(cls, *args, **kwargs):
  28         real_cls = cls._get_real_class()
  29         instance = real_cls.__new__(real_cls)
  30         instance.__init__(*args, **kwargs)
  31         return instance