|View source on GitHub|
Atomically decrements a key's value.
google.appengine.api.memcache.decr( key, delta=1, namespace=None, initial_value=None )
Internally, the value is a unsigned 64-bit integer. Memcache caps decrementing below zero to zero.
The key must already exist in the cache to be decremented. See
incr() for details.
||Key to decrement. If an iterable collection, each one of the keys will be offset. See Client's docstring for details.|
||Non-negative integer value (int or long) to decrement key by, defaulting to 1.|
||a string specifying an optional namespace to use in the request.|
||initial value to put in the cache, if it doesn't already exist. The default value, None, will not create a cache entry if it doesn't already exist.|
If key was a single value, the new long integer value, or None if key
was not in the cache, could not be decremented for any other reason, or
a network/RPC/server error occurred.
If key was an iterable collection, a dictionary will be returned mapping supplied keys to values, with the values having the same meaning as the singular return value of this method.
||If number is negative.|
||If delta isn't an int or long.|