pip install cache
import pylibmc
from cache import Cache
backend = pylibmc.Client(["127.0.0.1"])
cache = Cache(backend)
@cache("mykey")
def some_expensive_method():
sleep(10)
return 42
# writes 42 to the cache
some_expensive_method()
# reads 42 from the cache
some_expensive_method()
# re-calculates and writes 42 to the cache
some_expensive_method.refresh()
# get the cached value or throw an error
# (unless default= was passed to @cache(...))
some_expensive_method.cached()Options can be passed to either the Cache constructor or the decorator. Options passed to the decorator take precedence. Available options are:
enabled If `False`, the backend cache will not be used at all,
and your functions will be run as-is, even when you call
`.cached()`. This is useful for development, when the
function may be changing rapidly.
Default: True
bust If `True`, the values in the backend cache will be
ignored, and new data will be calculated and written
over the old values.
Default: False
default If given, `.cached()` will return the given value instead
of raising a KeyError.
The remaining options, if given, will be passed as keyword arguments to the backend's set method. This is useful for things like expiration times - for example, using pylibmc:
@cache("some_key", time=1000)
def expensive_method():
# ...Cache provides two "fake" caches for local development without a backend cache: LocalCache and NullCache. LocalCache uses a dictionary in place of a backend cache, and NullCache is a noop on set and always returns None on get.
The difference between passing enabled=False to the cache and using NullCache comes in when you use the .cached() method. If the cache is disabled, .cached() will run the underlying function, but NullCache will throw a KeyError as if the key was not present.
If you're a Ruby user, check out the analogous Cacher library for Ruby