Source code for heat.db.utils

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[docs]class LazyPluggable(object): """A pluggable backend loaded lazily based on some value.""" def __init__(self, pivot, **backends): self.__backends = backends self.__pivot = pivot self.__backend = None def __get_backend(self): if not self.__backend: backend_name = 'sqlalchemy' backend = self.__backends[backend_name] if isinstance(backend, tuple): name = backend[0] fromlist = backend[1] else: name = backend fromlist = backend self.__backend = __import__(name, None, None, fromlist) return self.__backend def __getattr__(self, key): backend = self.__get_backend() return getattr(backend, key)