Mercurial > cpython-lru_cache-weakref

annotate Doc/includes/sqlite3/collation_reverse.py @ 87690:66c1c9f32567 default tip

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Add use_weakref option to functools.lru_cache The use_weakref option makes lru_cache create weak references to the function arguments when creating the cache key, which prevents them from staying in the memory forever even after all other references to them are gone. This is a proof of concept for http://bugs.python.org/issue19859
author Radomir Dopieralski <devel@sheep.art.pl>
date Tue, 03 Dec 2013 16:02:48 +0100
parents 2358299564ea
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
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1 import sqlite3
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2
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3 def collate_reverse(string1, string2):
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4 if string1 == string2:
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5 return 0
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6 elif string1 < string2:
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7 return 1
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8 else:
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9 return -1
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10
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11 con = sqlite3.connect(":memory:")
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12 con.create_collation("reverse", collate_reverse)
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13
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14 cur = con.cursor()
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15 cur.execute("create table test(x)")
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16 cur.executemany("insert into test(x) values (?)", [("a",), ("b",)])
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17 cur.execute("select x from test order by x collate reverse")
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18 for row in cur:
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19 print(row)
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20 con.close()