ubelt.util_memoize module

ubelt.util_memoize.memoize(func)

memoization decorator that respects args and kwargs

References

https://wiki.python.org/moin/PythonDecoratorLibrary#Memoize

Parameters:func (function) – live python function Returns:memoized wrapper Return type:func

CommandLine:

python -m ubelt.util_decor memoize

Example

>>> import ubelt as ub
>>> closure = {'a': 'b', 'c': 'd'}
>>> incr = [0]
>>> def foo(key):
>>>     value = closure[key]
>>>     incr[0] += 1
>>>     return value
>>> foo_memo = ub.memoize(foo)
>>> assert foo('a') == 'b' and foo('c') == 'd'
>>> assert incr[0] == 2
>>> print('Call memoized version')
>>> assert foo_memo('a') == 'b' and foo_memo('c') == 'd'
>>> assert incr[0] == 4
>>> assert foo_memo('a') == 'b' and foo_memo('c') == 'd'
>>> print('Counter should no longer increase')
>>> assert incr[0] == 4
>>> print('Closure changes result without memoization')
>>> closure = {'a': 0, 'c': 1}
>>> assert foo('a') == 0 and foo('c') == 1
>>> assert incr[0] == 6
>>> assert foo_memo('a') == 'b' and foo_memo('c') == 'd'

class ubelt.util_memoize.memoize_method(func)

Bases: object

memoization decorator for a method that respects args and kwargs

References

http://code.activestate.com/recipes/577452-a-memoize-decorator-for-instance-methods/

Example

>>> import ubelt as ub
>>> closure = {'a': 'b', 'c': 'd'}
>>> incr = [0]
>>> class Foo(object):
>>>     @memoize_method
>>>     def foo_memo(self, key):
>>>         value = closure[key]
>>>         incr[0] += 1
>>>         return value
>>>     def foo(self, key):
>>>         value = closure[key]
>>>         incr[0] += 1
>>>         return value
>>> self = Foo()
>>> assert self.foo('a') == 'b' and self.foo('c') == 'd'
>>> assert incr[0] == 2
>>> print('Call memoized version')
>>> assert self.foo_memo('a') == 'b' and self.foo_memo('c') == 'd'
>>> assert incr[0] == 4
>>> assert self.foo_memo('a') == 'b' and self.foo_memo('c') == 'd'
>>> print('Counter should no longer increase')
>>> assert incr[0] == 4
>>> print('Closure changes result without memoization')
>>> closure = {'a': 0, 'c': 1}
>>> assert self.foo('a') == 0 and self.foo('c') == 1
>>> assert incr[0] == 6
>>> assert self.foo_memo('a') == 'b' and self.foo_memo('c') == 'd'
>>> print('Constructing a new object should get a new cache')
>>> self2 = Foo()
>>> self2.foo_memo('a')
>>> assert incr[0] == 7
>>> self2.foo_memo('a')
>>> assert incr[0] == 7