本文整理匯總了Python中sqlalchemy.orm.collections.collection.replaces方法的典型用法代碼示例。如果您正苦於以下問題：Python collection.replaces方法的具體用法？Python collection.replaces怎麽用？Python collection.replaces使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類sqlalchemy.orm.collections.collection的用法示例。
在下文中一共展示了collection.replaces方法的6個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的Python代碼示例。
示例1: replaces
# 需要導入模塊: from sqlalchemy.orm.collections import collection [as 別名]
# 或者: from sqlalchemy.orm.collections.collection import replaces [as 別名]
def replaces(arg):
"""Mark the method as replacing an entity in the collection.
Adds "add to collection" and "remove from collection" handling to
the method. The decorator argument indicates which method argument
holds the SQLAlchemy-relevant value to be added, and return value, if
any will be considered the value to remove.
Arguments can be specified positionally (i.e. integer) or by name::
@collection.replaces(2)
def __setitem__(self, index, item): ...
"""
def decorator(fn):
fn._sa_instrument_before = ('fire_append_event', arg)
fn._sa_instrument_after = 'fire_remove_event'
return fn
return decorator 示例2: replaces
# 需要導入模塊: from sqlalchemy.orm.collections import collection [as 別名]
# 或者: from sqlalchemy.orm.collections.collection import replaces [as 別名]
def replaces(arg):
"""Mark the method as replacing an entity in the collection.
Adds "add to collection" and "remove from collection" handling to
the method. The decorator argument indicates which method argument
holds the SQLAlchemy-relevant value to be added, and return value, if
any will be considered the value to remove.
Arguments can be specified positionally (i.e. integer) or by name::
@collection.replaces(2)
def __setitem__(self, index, item): ...
"""
def decorator(fn):
fn._sa_instrument_before = ("fire_append_event", arg)
fn._sa_instrument_after = "fire_remove_event"
return fn
return decorator 示例3: appender
# 需要導入模塊: from sqlalchemy.orm.collections import collection [as 別名]
# 或者: from sqlalchemy.orm.collections.collection import replaces [as 別名]
def appender(fn):
"""Tag the method as the collection appender.
The appender method is called with one positional argument: the value
to append. The method will be automatically decorated with 'adds(1)'
if not already decorated::
@collection.appender
def add(self, append): ...
# or, equivalently
@collection.appender
@collection.adds(1)
def add(self, append): ...
# for mapping type, an 'append' may kick out a previous value
# that occupies that slot. consider d['a'] = 'foo'- any previous
# value in d['a'] is discarded.
@collection.appender
@collection.replaces(1)
def add(self, entity):
key = some_key_func(entity)
previous = None
if key in self:
previous = self[key]
self[key] = entity
return previous
If the value to append is not allowed in the collection, you may
raise an exception. Something to remember is that the appender
will be called for each object mapped by a database query. If the
database contains rows that violate your collection semantics, you
will need to get creative to fix the problem, as access via the
collection will not work.
If the appender method is internally instrumented, you must also
receive the keyword argument '_sa_initiator' and ensure its
promulgation to collection events.
"""
fn._sa_instrument_role = 'appender'
return fn 示例4: appender
# 需要導入模塊: from sqlalchemy.orm.collections import collection [as 別名]
# 或者: from sqlalchemy.orm.collections.collection import replaces [as 別名]
def appender(fn):
"""Tag the method as the collection appender.
The appender method is called with one positional argument: the value
to append. The method will be automatically decorated with 'adds(1)'
if not already decorated::
@collection.appender
def add(self, append): ...
# or, equivalently
@collection.appender
@collection.adds(1)
def add(self, append): ...
# for mapping type, an 'append' may kick out a previous value
# that occupies that slot. consider d['a'] = 'foo'- any previous
# value in d['a'] is discarded.
@collection.appender
@collection.replaces(1)
def add(self, entity):
key = some_key_func(entity)
previous = None
if key in self:
previous = self[key]
self[key] = entity
return previous
If the value to append is not allowed in the collection, you may
raise an exception. Something to remember is that the appender
will be called for each object mapped by a database query. If the
database contains rows that violate your collection semantics, you
will need to get creative to fix the problem, as access via the
collection will not work.
If the appender method is internally instrumented, you must also
receive the keyword argument '_sa_initiator' and ensure its
promulgation to collection events.
"""
fn._sa_instrument_role = "appender"
return fn 示例5: test_dict_duck
# 需要導入模塊: from sqlalchemy.orm.collections import collection [as 別名]
# 或者: from sqlalchemy.orm.collections.collection import replaces [as 別名]
def test_dict_duck(self):
class DictLike(object):
def __init__(self):
self.data = dict()
@collection.appender
@collection.replaces(1)
def set(self, item):
current = self.data.get(item.a, None)
self.data[item.a] = item
return current
@collection.remover
def _remove(self, item):
del self.data[item.a]
def __setitem__(self, key, value):
self.data[key] = value
def __getitem__(self, key):
return self.data[key]
def __delitem__(self, key):
del self.data[key]
def values(self):
return list(self.data.values())
def __contains__(self, key):
return key in self.data
@collection.iterator
def itervalues(self):
return iter(self.data.values())
__hash__ = object.__hash__
def __eq__(self, other):
return self.data == other
def __repr__(self):
return "DictLike(%s)" % repr(self.data)
self._test_adapter(
DictLike, self.dictable_entity, to_set=lambda c: set(c.values())
)
self._test_dict(DictLike)
self._test_dict_bulk(DictLike)
self.assert_(getattr(DictLike, "_sa_instrumented") == id(DictLike)) 示例6: test_dict_emulates
# 需要導入模塊: from sqlalchemy.orm.collections import collection [as 別名]
# 或者: from sqlalchemy.orm.collections.collection import replaces [as 別名]
def test_dict_emulates(self):
class DictIsh(object):
__emulates__ = dict
def __init__(self):
self.data = dict()
@collection.appender
@collection.replaces(1)
def set(self, item):
current = self.data.get(item.a, None)
self.data[item.a] = item
return current
@collection.remover
def _remove(self, item):
del self.data[item.a]
def __setitem__(self, key, value):
self.data[key] = value
def __getitem__(self, key):
return self.data[key]
def __delitem__(self, key):
del self.data[key]
def values(self):
return list(self.data.values())
def __contains__(self, key):
return key in self.data
@collection.iterator
def itervalues(self):
return iter(self.data.values())
__hash__ = object.__hash__
def __eq__(self, other):
return self.data == other
def __repr__(self):
return "DictIsh(%s)" % repr(self.data)
self._test_adapter(
DictIsh, self.dictable_entity, to_set=lambda c: set(c.values())
)
self._test_dict(DictIsh)
self._test_dict_bulk(DictIsh)
self.assert_(getattr(DictIsh, "_sa_instrumented") == id(DictIsh))