字符向量被强制 [英] Character vector is being coerced

问题描述

我正在执行此简单命令，该命令使用字符串"A"，并使用空格将其拆分为单词.现在，将此单词向量传递给replace方法，在该方法中，它将看起来像完整数字的所有内容替换为"P12".但是最后的操作使输出变得混乱

I am doing this simple command where it takes a string "A" and splits it into words using space. Now pipe this vector of words to a replace method where it replaces anything that looks like a complete number to "P12". But the output is getting messy by doing the last operation

 A <- list(c("a12, 34, 35, 46"),c("ab14, 44, 55, 66"))
    B <- stringr::str_split(A, "[[:space:]]") %>% str_replace(pattern = "^[:digit:]{1,}[,]{1}$", replacement = "p12")

输出:

[1] "c(\"a12,\", \"34,\", \"35,\", \"46\")"

已更新:所需的输出应包含两个字符向量，这些向量存储在名为B的列表中:

Updated: desired output should contain two character vectors stored in a list named B:

[1] list(c("a12", "34", "35", "46"), c("ab14", "44", "55", "66"))

已回答了这一部分.谢谢！ 还请帮助正则表达式.当我使用下面的命令时，46并没有被替换.我应该如何确保1)文本是一个完整的数字，后跟一个逗号，或者没有逗号被"p12"替换?

This part is answered. Thank you! Also please help with regex. When I use the command below, 46 is not being replaced. How should I ensure if 1) the text is a complete number followed by a comma or no comma gets replaced by "p12"

str_replace(c("a12,", "34,", "35,", "46"), pattern = "^[:digit:]{1,}[,]{1}$", replacement = "p12")

输出:

"a12," "p12"  "p12"  "46"

所需:

"a12," "p12"  "p12"  "p12"

任何帮助将不胜感激

推荐答案

str_split返回字符向量列表.您只想unlist().它不直观，但是可以处理字符向量输入(每个元素一个列表).

str_split returns a list of character vectors. You just want to unlist(). It's not intuitive, but it's so it can handle a character vector input (one list for every element).

关于正则表达式，最后一个数字没有逗号.尝试让它与0或1个逗号匹配:

Regarding the regex, there isn't a comma on the final number. Try allowing it to match with 0 or 1 commas:

library(dplyr)
library(stringr)
A <- "a12, 34, 35, 46"
str_split(A, "[[:space:]]") %>% 
  unlist() %>% 
  str_replace(pattern = "^[:digit:]{1,}[,]{0,1}$", replacement = "p12")

输出:

#[1] "a12," "p12"  "p12"  "p12"

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