def counter(self, key, delta=1, initial=None, ttl=0):
"""Increment or decrement the numeric value of an item.
This method instructs the server to treat the item stored under
the given key as a numeric counter.
Counter operations require that the stored value
exists as a string representation of a number (e.g. ``123``). If
storing items using the :meth:`upsert` family of methods, and
using the default :const:`couchbase_v2.FMT_JSON` then the value
will conform to this constraint.
:param string key: A key whose counter value is to be modified
:param int delta: an amount by which the key should be modified.
If the number is negative then this number will be
*subtracted* from the current value.
:param initial: The initial value for the key, if it does not
exist. If the key does not exist, this value is used, and
`delta` is ignored. If this parameter is `None` then no
initial value is used
:type initial: int or `None`
:param int ttl: The lifetime for the key, after which it will
expire
:raise: :exc:`.DocumentNotFoundException` if the key does not exist on the
bucket (and `initial` was `None`)
:raise: :exc:`.DeltaBadvalException` if the key exists, but the
existing value is not numeric
:return: A :class:`.Result` object. The current value of the
counter may be obtained by inspecting the return value's
`value` attribute.
Simple increment::
rv = cb.counter("key")
rv.value
# 42
Increment by 10::
rv = cb.counter("key", delta=10)
Decrement by 5::
rv = cb.counter("key", delta=-5)
Increment by 20, set initial value to 5 if it does not exist::
rv = cb.counter("key", delta=20, initial=5)
Increment three keys::
kv = cb.counter_multi(["foo", "bar", "baz"])
for key, result in kv.items():
print "Key %s has value %d now" % (key, result.value)
.. seealso:: :meth:`counter_multi`
"""
return _Base.counter(self, key, delta=delta, initial=initial, ttl=ttl)
def decrement(self,
id, # type: str
delta, # type: DeltaValue
*options, # type: CounterOptions
**kwargs
):
# type: (...)->ResultPrecursor
"""Decrement the numeric value of an item.
This method instructs the server to treat the item stored under
the given key as a numeric counter.
Counter operations require that the stored value
exists as a string representation of a number (e.g. ``123``). If
storing items using the :meth:`upsert` family of methods, and
using the default :const:`couchbase_core.FMT_JSON` then the value
will conform to this constraint.
:param string key: A key whose counter value is to be modified
:param DeltaValue delta: an amount by which the key should be decremented.
:param couchbase.options.SignedInt64 initial: The initial value for the key, if it does not
exist. If the key does not exist, this value is used, and
`delta` is ignored. If this parameter is `None` then no
initial value is used
:param SignedInt64 initial: :class:`couchbase.options.SignedInt64` or `None`
:param Seconds expiration: The lifetime for the key, after which it will
expire
:raise: :exc:`.NotFoundError` if the key does not exist on the
bucket (and `initial` was `None`)
:raise: :exc:`.DeltaBadvalError` if the key exists, but the
existing value is not numeric
:return: A :class:`couchbase.result.MutationResult` object.
Simple decrement::
rv = cb.decrement("key")
cb.get("key").content_as[int]
# 42
Decrement by 10::
rv = cb.decrement("key", DeltaValue(10))
Decrement by 20, set initial value to 5 if it does not exist::
rv = cb.decrement("key", DeltaValue(20), initial=SignedInt64(5))
"""
final_opts = self._check_delta_initial(kwargs, *options)
final_opts = self._check_delta_initial(kwargs, *options)
x = _Base.counter(self.bucket, id, delta=-int(DeltaValue.verified(delta)), **final_opts)
return ResultPrecursor(x, final_opts)
