带有重叠子串的 str_count [英] str_count with overlapping substrings

问题描述

我正在尝试计算字符向量中子字符串的出现次数.例如:

I am trying to count the number of appearances of a substring within a character vector. For example:

lookin<-c("babababa", "bellow", "ra;baba")
searchfor<-"aba"
str_count(lookin, searchfor)

返回:2 0 1

但是，我希望它返回 '3 0 1' 但它没有在第一项中的中间 'aba' 上找到，因为它在第一个实例中被部分使用(我认为).

However, I want it to return '3 0 1' but it isn't picking up on the middle 'aba' in the first item since it is partially used in the first instance (I think).

我发现了这个问题无法弄清楚如何将其用于具有多个项目的向量.

I found this question but couldn't figure out how to use that with a vector having multiple items.

推荐答案

尝试:

str_count(lookin, paste0("(?=",searchfor,")"))

[1] 3 0 1

正如您的链接中所回答的那样，使用前瞻来匹配所有实例.

Which, as answered in your link, uses lookahead to match all instances.

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