python关键字以什么开头_查找关键字以相同前缀开头的字典值的更有效方法

您可以避免生成dict.keys()(在python2.x中)生成的中间列表&＃xff1a;result &＃61; [d[key] for key in d if key.startswith(query)]

但是您很可能希望使用trie而不是字典&＃xff0c;这样您就可以找到与具有公共前缀的键相关联的所有值(trie类似于基于前缀的树)。在

Here您可以找到一些不同的尝试实现。在

A trie for keys "A", "to", "tea", "ted", "ten", "i", "in", and "inn". (source wikipedia)

让我们比较一下不同解决方案的时间安排&＃xff1a;

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# dict without keys()

%timeit [d[s] for s in d if s.startswith(query)]

100 loops, best of 3: 7.83 ms per loop

# 11.72% improvement# PyTrie (https://pypi.python.org/pypi/PyTrie/0.2)

import pytrie

pt &＃61; pytrie.Trie(d)

%timeit [pt[s] for s in pt.iterkeys(query)]

1000 loops, best of 3: 320 µs per loop

# 96.36% improvement# datrie (https://pypi.python.org/pypi/datrie/0.7)

import datrie

dt &＃61; datrie.Trie(&＃39;0123456789&＃39;)

for key, val in d.iteritems():

dt[unicode(key)] &＃61; val

%timeit [dt[s] for s in dt.keys(unicode(query))]

10000 loops, best of 3: 162 µs per loop

# 98.17% improvement