diff options
Diffstat (limited to 'lib/sqlalchemy/orm/mapper.py')
| -rw-r--r-- | lib/sqlalchemy/orm/mapper.py | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py index 0d87a9c40..91e3251e2 100644 --- a/lib/sqlalchemy/orm/mapper.py +++ b/lib/sqlalchemy/orm/mapper.py @@ -1483,11 +1483,14 @@ class Mapper(sql_base.HasCacheKey, InspectionAttr): # it to mapped ColumnProperty try: self.polymorphic_on = self._props[self.polymorphic_on] - except KeyError: - raise sa_exc.ArgumentError( - "Can't determine polymorphic_on " - "value '%s' - no attribute is " - "mapped to this name." % self.polymorphic_on + except KeyError as err: + util.raise_( + sa_exc.ArgumentError( + "Can't determine polymorphic_on " + "value '%s' - no attribute is " + "mapped to this name." % self.polymorphic_on + ), + replace_context=err, ) if self.polymorphic_on in self._columntoproperty: @@ -1987,9 +1990,12 @@ class Mapper(sql_base.HasCacheKey, InspectionAttr): try: return self._props[key] - except KeyError: - raise sa_exc.InvalidRequestError( - "Mapper '%s' has no property '%s'" % (self, key) + except KeyError as err: + util.raise_( + sa_exc.InvalidRequestError( + "Mapper '%s' has no property '%s'" % (self, key) + ), + replace_context=err, ) def get_property_by_column(self, column): |