devscripts/lazy_load_template.py

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