853 lines
31 KiB
Python
853 lines
31 KiB
Python
# ext/declarative/base.py
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# Copyright (C) 2005-2020 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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"""Internal implementation for declarative."""
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import collections
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import weakref
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from sqlalchemy.orm import instrumentation
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from . import clsregistry
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from ... import event
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from ... import exc
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from ... import util
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from ...orm import class_mapper
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from ...orm import exc as orm_exc
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from ...orm import mapper
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from ...orm import mapperlib
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from ...orm import synonym
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from ...orm.attributes import QueryableAttribute
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from ...orm.base import _is_mapped_class
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from ...orm.base import InspectionAttr
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from ...orm.interfaces import MapperProperty
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from ...orm.properties import ColumnProperty
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from ...orm.properties import CompositeProperty
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from ...schema import Column
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from ...schema import Table
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from ...sql import expression
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from ...util import topological
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declared_attr = declarative_props = None
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def _declared_mapping_info(cls):
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# deferred mapping
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if _DeferredMapperConfig.has_cls(cls):
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return _DeferredMapperConfig.config_for_cls(cls)
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# regular mapping
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elif _is_mapped_class(cls):
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return class_mapper(cls, configure=False)
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else:
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return None
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def _resolve_for_abstract_or_classical(cls):
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if cls is object:
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return None
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if _get_immediate_cls_attr(cls, "__abstract__", strict=True):
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for sup in cls.__bases__:
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sup = _resolve_for_abstract_or_classical(sup)
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if sup is not None:
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return sup
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else:
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return None
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else:
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classical = _dive_for_classically_mapped_class(cls)
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if classical is not None:
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return classical
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else:
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return cls
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def _dive_for_classically_mapped_class(cls):
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# support issue #4321
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# if we are within a base hierarchy, don't
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# search at all for classical mappings
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if hasattr(cls, "_decl_class_registry"):
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return None
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manager = instrumentation.manager_of_class(cls)
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if manager is not None:
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return cls
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else:
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for sup in cls.__bases__:
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mapper = _dive_for_classically_mapped_class(sup)
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if mapper is not None:
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return sup
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else:
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return None
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def _get_immediate_cls_attr(cls, attrname, strict=False):
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"""return an attribute of the class that is either present directly
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on the class, e.g. not on a superclass, or is from a superclass but
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this superclass is a non-mapped mixin, that is, not a descendant of
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the declarative base and is also not classically mapped.
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This is used to detect attributes that indicate something about
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a mapped class independently from any mapped classes that it may
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inherit from.
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"""
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if not issubclass(cls, object):
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return None
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for base in cls.__mro__:
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_is_declarative_inherits = hasattr(base, "_decl_class_registry")
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_is_classicial_inherits = (
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not _is_declarative_inherits
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and _dive_for_classically_mapped_class(base) is not None
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)
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if attrname in base.__dict__ and (
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base is cls
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or (
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(base in cls.__bases__ if strict else True)
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and not _is_declarative_inherits
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and not _is_classicial_inherits
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)
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):
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return getattr(base, attrname)
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else:
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return None
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def _as_declarative(cls, classname, dict_):
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global declared_attr, declarative_props
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if declared_attr is None:
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from .api import declared_attr
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declarative_props = (declared_attr, util.classproperty)
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if _get_immediate_cls_attr(cls, "__abstract__", strict=True):
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return
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_MapperConfig.setup_mapping(cls, classname, dict_)
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def _check_declared_props_nocascade(obj, name, cls):
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if isinstance(obj, declarative_props):
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if getattr(obj, "_cascading", False):
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util.warn(
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"@declared_attr.cascading is not supported on the %s "
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"attribute on class %s. This attribute invokes for "
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"subclasses in any case." % (name, cls)
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)
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return True
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else:
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return False
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class _MapperConfig(object):
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@classmethod
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def setup_mapping(cls, cls_, classname, dict_):
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defer_map = _get_immediate_cls_attr(
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cls_, "_sa_decl_prepare_nocascade", strict=True
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) or hasattr(cls_, "_sa_decl_prepare")
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if defer_map:
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cfg_cls = _DeferredMapperConfig
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else:
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cfg_cls = _MapperConfig
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cfg_cls(cls_, classname, dict_)
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def __init__(self, cls_, classname, dict_):
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self.cls = cls_
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# dict_ will be a dictproxy, which we can't write to, and we need to!
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self.dict_ = dict(dict_)
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self.classname = classname
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self.persist_selectable = None
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self.properties = util.OrderedDict()
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self.declared_columns = set()
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self.column_copies = {}
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self._setup_declared_events()
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# temporary registry. While early 1.0 versions
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# set up the ClassManager here, by API contract
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# we can't do that until there's a mapper.
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self.cls._sa_declared_attr_reg = {}
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self._scan_attributes()
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mapperlib._CONFIGURE_MUTEX.acquire()
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try:
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clsregistry.add_class(self.classname, self.cls)
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self._extract_mappable_attributes()
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self._extract_declared_columns()
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self._setup_table()
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self._setup_inheritance()
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self._early_mapping()
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finally:
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mapperlib._CONFIGURE_MUTEX.release()
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def _early_mapping(self):
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self.map()
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def _setup_declared_events(self):
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if _get_immediate_cls_attr(self.cls, "__declare_last__"):
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@event.listens_for(mapper, "after_configured")
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def after_configured():
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self.cls.__declare_last__()
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if _get_immediate_cls_attr(self.cls, "__declare_first__"):
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@event.listens_for(mapper, "before_configured")
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def before_configured():
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self.cls.__declare_first__()
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def _scan_attributes(self):
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cls = self.cls
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dict_ = self.dict_
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column_copies = self.column_copies
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mapper_args_fn = None
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table_args = inherited_table_args = None
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tablename = None
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for base in cls.__mro__:
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class_mapped = (
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base is not cls
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and _declared_mapping_info(base) is not None
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and not _get_immediate_cls_attr(
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base, "_sa_decl_prepare_nocascade", strict=True
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)
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)
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if not class_mapped and base is not cls:
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self._produce_column_copies(base)
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for name, obj in vars(base).items():
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if name == "__mapper_args__":
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check_decl = _check_declared_props_nocascade(
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obj, name, cls
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)
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if not mapper_args_fn and (not class_mapped or check_decl):
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# don't even invoke __mapper_args__ until
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# after we've determined everything about the
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# mapped table.
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# make a copy of it so a class-level dictionary
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# is not overwritten when we update column-based
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# arguments.
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def mapper_args_fn():
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return dict(cls.__mapper_args__)
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elif name == "__tablename__":
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check_decl = _check_declared_props_nocascade(
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obj, name, cls
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)
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if not tablename and (not class_mapped or check_decl):
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tablename = cls.__tablename__
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elif name == "__table_args__":
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check_decl = _check_declared_props_nocascade(
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obj, name, cls
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)
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if not table_args and (not class_mapped or check_decl):
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table_args = cls.__table_args__
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if not isinstance(
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table_args, (tuple, dict, type(None))
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):
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raise exc.ArgumentError(
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"__table_args__ value must be a tuple, "
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"dict, or None"
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)
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if base is not cls:
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inherited_table_args = True
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elif class_mapped:
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if isinstance(obj, declarative_props):
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util.warn(
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"Regular (i.e. not __special__) "
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"attribute '%s.%s' uses @declared_attr, "
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"but owning class %s is mapped - "
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"not applying to subclass %s."
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% (base.__name__, name, base, cls)
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)
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continue
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elif base is not cls:
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# we're a mixin, abstract base, or something that is
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# acting like that for now.
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if isinstance(obj, Column):
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# already copied columns to the mapped class.
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continue
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elif isinstance(obj, MapperProperty):
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raise exc.InvalidRequestError(
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"Mapper properties (i.e. deferred,"
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"column_property(), relationship(), etc.) must "
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"be declared as @declared_attr callables "
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"on declarative mixin classes."
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)
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elif isinstance(obj, declarative_props):
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oldclassprop = isinstance(obj, util.classproperty)
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if not oldclassprop and obj._cascading:
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if name in dict_:
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# unfortunately, while we can use the user-
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# defined attribute here to allow a clean
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# override, if there's another
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# subclass below then it still tries to use
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# this. not sure if there is enough
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# information here to add this as a feature
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# later on.
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util.warn(
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"Attribute '%s' on class %s cannot be "
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"processed due to "
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"@declared_attr.cascading; "
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"skipping" % (name, cls)
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)
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dict_[name] = column_copies[
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obj
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] = ret = obj.__get__(obj, cls)
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setattr(cls, name, ret)
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else:
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if oldclassprop:
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util.warn_deprecated(
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"Use of sqlalchemy.util.classproperty on "
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"declarative classes is deprecated."
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)
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# access attribute using normal class access
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ret = getattr(cls, name)
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# correct for proxies created from hybrid_property
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# or similar. note there is no known case that
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# produces nested proxies, so we are only
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# looking one level deep right now.
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if (
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isinstance(ret, InspectionAttr)
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and ret._is_internal_proxy
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and not isinstance(
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ret.original_property, MapperProperty
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)
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):
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ret = ret.descriptor
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dict_[name] = column_copies[obj] = ret
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if (
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isinstance(ret, (Column, MapperProperty))
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and ret.doc is None
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):
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ret.doc = obj.__doc__
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# here, the attribute is some other kind of property that
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# we assume is not part of the declarative mapping.
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# however, check for some more common mistakes
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else:
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self._warn_for_decl_attributes(base, name, obj)
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if inherited_table_args and not tablename:
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table_args = None
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self.table_args = table_args
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self.tablename = tablename
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self.mapper_args_fn = mapper_args_fn
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def _warn_for_decl_attributes(self, cls, key, c):
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if isinstance(c, expression.ColumnClause):
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util.warn(
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"Attribute '%s' on class %s appears to be a non-schema "
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"'sqlalchemy.sql.column()' "
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"object; this won't be part of the declarative mapping"
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% (key, cls)
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)
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def _produce_column_copies(self, base):
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cls = self.cls
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dict_ = self.dict_
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column_copies = self.column_copies
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# copy mixin columns to the mapped class
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for name, obj in vars(base).items():
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if isinstance(obj, Column):
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if getattr(cls, name) is not obj:
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# if column has been overridden
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# (like by the InstrumentedAttribute of the
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# superclass), skip
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continue
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elif obj.foreign_keys:
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raise exc.InvalidRequestError(
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"Columns with foreign keys to other columns "
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"must be declared as @declared_attr callables "
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"on declarative mixin classes. "
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)
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elif name not in dict_ and not (
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"__table__" in dict_
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and (obj.name or name) in dict_["__table__"].c
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):
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column_copies[obj] = copy_ = obj.copy()
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copy_._creation_order = obj._creation_order
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setattr(cls, name, copy_)
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dict_[name] = copy_
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def _extract_mappable_attributes(self):
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cls = self.cls
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dict_ = self.dict_
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our_stuff = self.properties
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late_mapped = _get_immediate_cls_attr(
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cls, "_sa_decl_prepare_nocascade", strict=True
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)
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for k in list(dict_):
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if k in ("__table__", "__tablename__", "__mapper_args__"):
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continue
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value = dict_[k]
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if isinstance(value, declarative_props):
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if isinstance(value, declared_attr) and value._cascading:
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util.warn(
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"Use of @declared_attr.cascading only applies to "
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"Declarative 'mixin' and 'abstract' classes. "
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"Currently, this flag is ignored on mapped class "
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"%s" % self.cls
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)
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value = getattr(cls, k)
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elif (
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isinstance(value, QueryableAttribute)
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and value.class_ is not cls
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and value.key != k
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):
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# detect a QueryableAttribute that's already mapped being
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# assigned elsewhere in userland, turn into a synonym()
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value = synonym(value.key)
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setattr(cls, k, value)
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if (
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isinstance(value, tuple)
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and len(value) == 1
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and isinstance(value[0], (Column, MapperProperty))
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):
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util.warn(
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"Ignoring declarative-like tuple value of attribute "
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"'%s': possibly a copy-and-paste error with a comma "
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"accidentally placed at the end of the line?" % k
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)
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continue
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elif not isinstance(value, (Column, MapperProperty)):
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# using @declared_attr for some object that
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# isn't Column/MapperProperty; remove from the dict_
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# and place the evaluated value onto the class.
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if not k.startswith("__"):
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dict_.pop(k)
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self._warn_for_decl_attributes(cls, k, value)
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if not late_mapped:
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setattr(cls, k, value)
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continue
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# we expect to see the name 'metadata' in some valid cases;
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# however at this point we see it's assigned to something trying
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# to be mapped, so raise for that.
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elif k == "metadata":
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raise exc.InvalidRequestError(
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"Attribute name 'metadata' is reserved "
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"for the MetaData instance when using a "
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"declarative base class."
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)
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prop = clsregistry._deferred_relationship(cls, value)
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our_stuff[k] = prop
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def _extract_declared_columns(self):
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our_stuff = self.properties
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# set up attributes in the order they were created
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our_stuff.sort(key=lambda key: our_stuff[key]._creation_order)
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# extract columns from the class dict
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declared_columns = self.declared_columns
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name_to_prop_key = collections.defaultdict(set)
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for key, c in list(our_stuff.items()):
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if isinstance(c, (ColumnProperty, CompositeProperty)):
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for col in c.columns:
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if isinstance(col, Column) and col.table is None:
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_undefer_column_name(key, col)
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if not isinstance(c, CompositeProperty):
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name_to_prop_key[col.name].add(key)
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declared_columns.add(col)
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elif isinstance(c, Column):
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_undefer_column_name(key, c)
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name_to_prop_key[c.name].add(key)
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declared_columns.add(c)
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# if the column is the same name as the key,
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# remove it from the explicit properties dict.
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# the normal rules for assigning column-based properties
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# will take over, including precedence of columns
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# in multi-column ColumnProperties.
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if key == c.key:
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del our_stuff[key]
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for name, keys in name_to_prop_key.items():
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if len(keys) > 1:
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util.warn(
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"On class %r, Column object %r named "
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"directly multiple times, "
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"only one will be used: %s. "
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"Consider using orm.synonym instead"
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% (self.classname, name, (", ".join(sorted(keys))))
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)
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def _setup_table(self):
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cls = self.cls
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tablename = self.tablename
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table_args = self.table_args
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dict_ = self.dict_
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declared_columns = self.declared_columns
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declared_columns = self.declared_columns = sorted(
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declared_columns, key=lambda c: c._creation_order
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)
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table = None
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if hasattr(cls, "__table_cls__"):
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table_cls = util.unbound_method_to_callable(cls.__table_cls__)
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else:
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table_cls = Table
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if "__table__" not in dict_:
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if tablename is not None:
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args, table_kw = (), {}
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if table_args:
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if isinstance(table_args, dict):
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table_kw = table_args
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elif isinstance(table_args, tuple):
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if isinstance(table_args[-1], dict):
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args, table_kw = table_args[0:-1], table_args[-1]
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else:
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args = table_args
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autoload = dict_.get("__autoload__")
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if autoload:
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table_kw["autoload"] = True
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cls.__table__ = table = table_cls(
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tablename,
|
|
cls.metadata,
|
|
*(tuple(declared_columns) + tuple(args)),
|
|
**table_kw
|
|
)
|
|
else:
|
|
table = cls.__table__
|
|
if declared_columns:
|
|
for c in declared_columns:
|
|
if not table.c.contains_column(c):
|
|
raise exc.ArgumentError(
|
|
"Can't add additional column %r when "
|
|
"specifying __table__" % c.key
|
|
)
|
|
self.local_table = table
|
|
|
|
def _setup_inheritance(self):
|
|
table = self.local_table
|
|
cls = self.cls
|
|
table_args = self.table_args
|
|
declared_columns = self.declared_columns
|
|
|
|
# since we search for classical mappings now, search for
|
|
# multiple mapped bases as well and raise an error.
|
|
inherits = []
|
|
for c in cls.__bases__:
|
|
c = _resolve_for_abstract_or_classical(c)
|
|
if c is None:
|
|
continue
|
|
if _declared_mapping_info(
|
|
c
|
|
) is not None and not _get_immediate_cls_attr(
|
|
c, "_sa_decl_prepare_nocascade", strict=True
|
|
):
|
|
inherits.append(c)
|
|
|
|
if inherits:
|
|
if len(inherits) > 1:
|
|
raise exc.InvalidRequestError(
|
|
"Class %s has multiple mapped bases: %r" % (cls, inherits)
|
|
)
|
|
self.inherits = inherits[0]
|
|
else:
|
|
self.inherits = None
|
|
|
|
if (
|
|
table is None
|
|
and self.inherits is None
|
|
and not _get_immediate_cls_attr(cls, "__no_table__")
|
|
):
|
|
|
|
raise exc.InvalidRequestError(
|
|
"Class %r does not have a __table__ or __tablename__ "
|
|
"specified and does not inherit from an existing "
|
|
"table-mapped class." % cls
|
|
)
|
|
elif self.inherits:
|
|
inherited_mapper = _declared_mapping_info(self.inherits)
|
|
inherited_table = inherited_mapper.local_table
|
|
inherited_persist_selectable = inherited_mapper.persist_selectable
|
|
|
|
if table is None:
|
|
# single table inheritance.
|
|
# ensure no table args
|
|
if table_args:
|
|
raise exc.ArgumentError(
|
|
"Can't place __table_args__ on an inherited class "
|
|
"with no table."
|
|
)
|
|
# add any columns declared here to the inherited table.
|
|
for c in declared_columns:
|
|
if c.name in inherited_table.c:
|
|
if inherited_table.c[c.name] is c:
|
|
continue
|
|
raise exc.ArgumentError(
|
|
"Column '%s' on class %s conflicts with "
|
|
"existing column '%s'"
|
|
% (c, cls, inherited_table.c[c.name])
|
|
)
|
|
if c.primary_key:
|
|
raise exc.ArgumentError(
|
|
"Can't place primary key columns on an inherited "
|
|
"class with no table."
|
|
)
|
|
inherited_table.append_column(c)
|
|
if (
|
|
inherited_persist_selectable is not None
|
|
and inherited_persist_selectable is not inherited_table
|
|
):
|
|
inherited_persist_selectable._refresh_for_new_column(c)
|
|
|
|
def _prepare_mapper_arguments(self):
|
|
properties = self.properties
|
|
if self.mapper_args_fn:
|
|
mapper_args = self.mapper_args_fn()
|
|
else:
|
|
mapper_args = {}
|
|
|
|
# make sure that column copies are used rather
|
|
# than the original columns from any mixins
|
|
for k in ("version_id_col", "polymorphic_on"):
|
|
if k in mapper_args:
|
|
v = mapper_args[k]
|
|
mapper_args[k] = self.column_copies.get(v, v)
|
|
|
|
assert (
|
|
"inherits" not in mapper_args
|
|
), "Can't specify 'inherits' explicitly with declarative mappings"
|
|
|
|
if self.inherits:
|
|
mapper_args["inherits"] = self.inherits
|
|
|
|
if self.inherits and not mapper_args.get("concrete", False):
|
|
# single or joined inheritance
|
|
# exclude any cols on the inherited table which are
|
|
# not mapped on the parent class, to avoid
|
|
# mapping columns specific to sibling/nephew classes
|
|
inherited_mapper = _declared_mapping_info(self.inherits)
|
|
inherited_table = inherited_mapper.local_table
|
|
|
|
if "exclude_properties" not in mapper_args:
|
|
mapper_args["exclude_properties"] = exclude_properties = set(
|
|
[
|
|
c.key
|
|
for c in inherited_table.c
|
|
if c not in inherited_mapper._columntoproperty
|
|
]
|
|
).union(inherited_mapper.exclude_properties or ())
|
|
exclude_properties.difference_update(
|
|
[c.key for c in self.declared_columns]
|
|
)
|
|
|
|
# look through columns in the current mapper that
|
|
# are keyed to a propname different than the colname
|
|
# (if names were the same, we'd have popped it out above,
|
|
# in which case the mapper makes this combination).
|
|
# See if the superclass has a similar column property.
|
|
# If so, join them together.
|
|
for k, col in list(properties.items()):
|
|
if not isinstance(col, expression.ColumnElement):
|
|
continue
|
|
if k in inherited_mapper._props:
|
|
p = inherited_mapper._props[k]
|
|
if isinstance(p, ColumnProperty):
|
|
# note here we place the subclass column
|
|
# first. See [ticket:1892] for background.
|
|
properties[k] = [col] + p.columns
|
|
result_mapper_args = mapper_args.copy()
|
|
result_mapper_args["properties"] = properties
|
|
self.mapper_args = result_mapper_args
|
|
|
|
def map(self):
|
|
self._prepare_mapper_arguments()
|
|
if hasattr(self.cls, "__mapper_cls__"):
|
|
mapper_cls = util.unbound_method_to_callable(
|
|
self.cls.__mapper_cls__
|
|
)
|
|
else:
|
|
mapper_cls = mapper
|
|
|
|
self.cls.__mapper__ = mp_ = mapper_cls(
|
|
self.cls, self.local_table, **self.mapper_args
|
|
)
|
|
del self.cls._sa_declared_attr_reg
|
|
return mp_
|
|
|
|
|
|
class _DeferredMapperConfig(_MapperConfig):
|
|
_configs = util.OrderedDict()
|
|
|
|
def _early_mapping(self):
|
|
pass
|
|
|
|
@property
|
|
def cls(self):
|
|
return self._cls()
|
|
|
|
@cls.setter
|
|
def cls(self, class_):
|
|
self._cls = weakref.ref(class_, self._remove_config_cls)
|
|
self._configs[self._cls] = self
|
|
|
|
@classmethod
|
|
def _remove_config_cls(cls, ref):
|
|
cls._configs.pop(ref, None)
|
|
|
|
@classmethod
|
|
def has_cls(cls, class_):
|
|
# 2.6 fails on weakref if class_ is an old style class
|
|
return isinstance(class_, type) and weakref.ref(class_) in cls._configs
|
|
|
|
@classmethod
|
|
def raise_unmapped_for_cls(cls, class_):
|
|
if hasattr(class_, "_sa_raise_deferred_config"):
|
|
class_._sa_raise_deferred_config()
|
|
|
|
raise orm_exc.UnmappedClassError(
|
|
class_,
|
|
msg="Class %s has a deferred mapping on it. It is not yet "
|
|
"usable as a mapped class." % orm_exc._safe_cls_name(class_),
|
|
)
|
|
|
|
@classmethod
|
|
def config_for_cls(cls, class_):
|
|
return cls._configs[weakref.ref(class_)]
|
|
|
|
@classmethod
|
|
def classes_for_base(cls, base_cls, sort=True):
|
|
classes_for_base = [
|
|
m
|
|
for m, cls_ in [(m, m.cls) for m in cls._configs.values()]
|
|
if cls_ is not None and issubclass(cls_, base_cls)
|
|
]
|
|
|
|
if not sort:
|
|
return classes_for_base
|
|
|
|
all_m_by_cls = dict((m.cls, m) for m in classes_for_base)
|
|
|
|
tuples = []
|
|
for m_cls in all_m_by_cls:
|
|
tuples.extend(
|
|
(all_m_by_cls[base_cls], all_m_by_cls[m_cls])
|
|
for base_cls in m_cls.__bases__
|
|
if base_cls in all_m_by_cls
|
|
)
|
|
return list(topological.sort(tuples, classes_for_base))
|
|
|
|
def map(self):
|
|
self._configs.pop(self._cls, None)
|
|
return super(_DeferredMapperConfig, self).map()
|
|
|
|
|
|
def _add_attribute(cls, key, value):
|
|
"""add an attribute to an existing declarative class.
|
|
|
|
This runs through the logic to determine MapperProperty,
|
|
adds it to the Mapper, adds a column to the mapped Table, etc.
|
|
|
|
"""
|
|
|
|
if "__mapper__" in cls.__dict__:
|
|
if isinstance(value, Column):
|
|
_undefer_column_name(key, value)
|
|
cls.__table__.append_column(value)
|
|
cls.__mapper__.add_property(key, value)
|
|
elif isinstance(value, ColumnProperty):
|
|
for col in value.columns:
|
|
if isinstance(col, Column) and col.table is None:
|
|
_undefer_column_name(key, col)
|
|
cls.__table__.append_column(col)
|
|
cls.__mapper__.add_property(key, value)
|
|
elif isinstance(value, MapperProperty):
|
|
cls.__mapper__.add_property(
|
|
key, clsregistry._deferred_relationship(cls, value)
|
|
)
|
|
elif isinstance(value, QueryableAttribute) and value.key != key:
|
|
# detect a QueryableAttribute that's already mapped being
|
|
# assigned elsewhere in userland, turn into a synonym()
|
|
value = synonym(value.key)
|
|
cls.__mapper__.add_property(
|
|
key, clsregistry._deferred_relationship(cls, value)
|
|
)
|
|
else:
|
|
type.__setattr__(cls, key, value)
|
|
cls.__mapper__._expire_memoizations()
|
|
else:
|
|
type.__setattr__(cls, key, value)
|
|
|
|
|
|
def _del_attribute(cls, key):
|
|
|
|
if (
|
|
"__mapper__" in cls.__dict__
|
|
and key in cls.__dict__
|
|
and not cls.__mapper__._dispose_called
|
|
):
|
|
value = cls.__dict__[key]
|
|
if isinstance(
|
|
value, (Column, ColumnProperty, MapperProperty, QueryableAttribute)
|
|
):
|
|
raise NotImplementedError(
|
|
"Can't un-map individual mapped attributes on a mapped class."
|
|
)
|
|
else:
|
|
type.__delattr__(cls, key)
|
|
cls.__mapper__._expire_memoizations()
|
|
else:
|
|
type.__delattr__(cls, key)
|
|
|
|
|
|
def _declarative_constructor(self, **kwargs):
|
|
"""A simple constructor that allows initialization from kwargs.
|
|
|
|
Sets attributes on the constructed instance using the names and
|
|
values in ``kwargs``.
|
|
|
|
Only keys that are present as
|
|
attributes of the instance's class are allowed. These could be,
|
|
for example, any mapped columns or relationships.
|
|
"""
|
|
cls_ = type(self)
|
|
for k in kwargs:
|
|
if not hasattr(cls_, k):
|
|
raise TypeError(
|
|
"%r is an invalid keyword argument for %s" % (k, cls_.__name__)
|
|
)
|
|
setattr(self, k, kwargs[k])
|
|
|
|
|
|
_declarative_constructor.__name__ = "__init__"
|
|
|
|
|
|
def _undefer_column_name(key, column):
|
|
if column.key is None:
|
|
column.key = key
|
|
if column.name is None:
|
|
column.name = key
|