Created
January 3, 2020 14:55
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Demonstration of how the Python lru_cache perhaps isn't necessarily efficient by default
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| """ | |
| Depending on the scenario, lru_cache() in functools may lead to inadvertent or | |
| at least unexpected cache misses. | |
| """ | |
| from functools import lru_cache | |
| eval_count = 0 | |
| @lru_cache(maxsize=128) | |
| def cached_fun(x): | |
| global eval_count | |
| eval_count += 1 | |
| return 2 * x | |
| cached_fun(2) | |
| assert eval_count == 1 | |
| cached_fun(2) | |
| assert eval_count == 1 | |
| cached_fun(x=2) | |
| # this would fail: identical values passed in as keyword | |
| # arguments are considered different from them defined via | |
| # the positional route :S | |
| # assert eval_count == 1 | |
| assert eval_count == 2 |
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