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# -*- coding: utf-8 -*- |
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from __future__ import absolute_import, division, print_function |
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from collections import Hashable |
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from types import GeneratorType |
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from six import wraps |
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def memoize(func): |
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""" |
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Decorator to cause a function to cache it's results for each combination of |
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inputs and return the cached result on subsequent calls. Does not support |
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named arguments or arg values that are not hashable. |
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>>> @memoize |
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... def foo(x): |
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... print('running function with', x) |
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... return x+3 |
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... |
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>>> foo(10) |
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running function with 10 |
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13 |
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>>> foo(10) |
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13 |
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>>> foo(11) |
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running function with 11 |
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14 |
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>>> @memoize |
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... def range_tuple(limit): |
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... print('running function') |
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... return tuple(i for i in range(limit)) |
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... |
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>>> range_tuple(3) |
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running function |
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(0, 1, 2) |
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>>> range_tuple(3) |
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(0, 1, 2) |
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>>> @memoize |
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... def range_iter(limit): |
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... print('running function') |
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... return (i for i in range(limit)) |
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... |
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>>> range_iter(3) |
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Traceback (most recent call last): |
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TypeError: Can't memoize a generator or non-hashable object! |
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""" |
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func._result_cache = {} # pylint: disable-msg=W0212 |
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@wraps(func) |
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def _memoized_func(*args, **kwargs): |
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key = (args, tuple(sorted(kwargs.items()))) |
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if key in func._result_cache: # pylint: disable-msg=W0212 |
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return func._result_cache[key] # pylint: disable-msg=W0212 |
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else: |
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result = func(*args, **kwargs) |
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if isinstance(result, GeneratorType) or not isinstance(result, Hashable): |
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raise TypeError("Can't memoize a generator or non-hashable object!") |
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func._result_cache[key] = result # pylint: disable-msg=W0212 |
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return result |
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return _memoized_func |
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Anaconda-Platform /
anaconda-client
