最好的方法来确定是否一个序列是在Python的另一个序列 [英] Best Way To Determine if a Sequence is in another sequence in Python

问题描述

这是一个泛化字符串包含子问题（更多）任意类型。

This is a generalization of the "string contains substring" problem to (more) arbitrary types.

给定一个序列（如列表或元组），什么是确定的另一个序列是里面的最好方法是什么？作为奖励，它应该返回的元素的索引序列开始的地方：

Given an sequence (such as a list or tuple), what's the best way of determining whether another sequence is inside it? As a bonus, it should return the index of the element where the subsequence starts:

用法示例（在顺序顺序）：

Example usage (Sequence in Sequence):

>>> seq_in_seq([5,6],  [4,'a',3,5,6])
3
>>> seq_in_seq([5,7],  [4,'a',3,5,6])
-1 # or None, or whatever

到目前为止，我只是靠蛮力，它似乎慢，丑陋，笨拙的。

So far, I just rely on brute force and it seems slow, ugly, and clumsy.

推荐答案

我第二高德纳 - 莫里斯 - 普拉特算法。顺便说一句，你的问题（KMP的解决方案）是完全配方5.13 Python的食谱的第二版。你可以找到相关的code在<一个href="http://$c$c.activestate.com/recipes/117214/">http://$c$c.activestate.com/recipes/117214/

I second the Knuth-Morris-Pratt algorithm. By the way, your problem (and the KMP solution) is exactly recipe 5.13 in Python Cookbook 2nd edition. You can find the related code at http://code.activestate.com/recipes/117214/

有发现的所有的在一个给定序列中的正确序列，并应作为一个迭代：

It finds all the correct subsequences in a given sequence, and should be used as an iterator:

>>> for s in KnuthMorrisPratt([4,'a',3,5,6], [5,6]): print s
3
>>> for s in KnuthMorrisPratt([4,'a',3,5,6], [5,7]): print s
(nothing)

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