执行:
这是一个 Aho-Corasick 频率计数器:
import ahocorasick
def ac_frequency(needles, haystack):
frequencies = [0] * len(needles)
# Make a searcher
searcher = ahocorasick.Automaton()
for i, needle in enumerate(needles):
searcher.add_word(needle, i)
searcher.make_automaton()
# Add up all frequencies
for _, i in searcher.iter(haystack):
frequencies[i] += 1
return frequencies
(对于您的示例,您会调用ac_frequency(my_list, my_string)
以获取计数列表)
对于中大型输入,这将比其他方法快得多。
笔记:
对于真实数据,此方法可能会产生与发布的其他解决方案不同的结果,因为 Aho-Corasick 会查找目标单词的所有出现,包括子字符串。
如果您只想查找完整的单词,您可以searcher.add_word
使用原始字符串的空格/标点符号填充版本进行调用:
...
padding_start = [" ", "\n", "\t"]
padding_end = [" ", ".", ";", ",", "-", "–", "—", "?", "!", "\n"]
for i, needle in enumerate(needles):
for s, e in [(s,e) for s in padding_start for e in padding_end]:
searcher.add_word(s + needle + e, i)
searcher.make_automaton()
# Add up all frequencies
for _, i in searcher.iter(" " + haystack + " "):
...