提问人：Ian 提问时间：12/7/2022 最后编辑：MaëlIan 更新时间：12/8/2022 访问量：101
给定字符集的所有可能序列
All possible sequences of given sets of characters
问：
我有以下字符串：
'[ABC][abcd][XYZ]'
我想生成所有可能的字符串，其中第一个字符是 A、B 或 C，第二个字符是 a、b、c 或 d，第三个字符是 X、Y 或 Z。
示例：AcX、BaZ 等。
如何做到这一点，最好是在 Tidyverse 中？
答：
7赞
jay.sf
12/7/2022
#1
首先适当地使用字符串来获取列表，然后使用 和 with 。splitstrexpand.gridpaste0do.call
el(strsplit('[ABC][abcd][XYZ]', '[\\[|\\]]', perl=TRUE)) |>
{\(x) x[x != '']}() |>
sapply(strsplit, '') |>
do.call(what=expand.grid) |>
do.call(what=paste0)
# [1] "AaX" "BaX" "CaX" "AbX" "BbX" "CbX" "AcX" "BcX" "CcX" "AdX" "BdX" "CdX" "AaY" "BaY" "CaY" "AbY" "BbY" "CbY" "AcY" "BcY"
# [21] "CcY" "AdY" "BdY" "CdY" "AaZ" "BaZ" "CaZ" "AbZ" "BbZ" "CbZ" "AcZ" "BcZ" "CcZ" "AdZ" "BdZ" "CdZ"
6赞
Maël
12/7/2022
#2
解决方案：stringr
library(stringr)
str_extract_all(x,"(?<=\\[).+?(?=\\])", simplify = TRUE) |>
str_split("") |>
expand.grid() |>
do.call(what = paste0)
# [1] "AaX" "BaX" "CaX" "AbX" "BbX" "CbX" "AcX" "BcX" "CcX" "AdX" "BdX" "CdX" "AaY" "BaY" "CaY" "AbY" "BbY" "CbY" "AcY" "BcY"
#[21] "CcY" "AdY" "BdY" "CdY" "AaZ" "BaZ" "CaZ" "AbZ" "BbZ" "CbZ" "AcZ" "BcZ" "CcZ" "AdZ" "BdZ" "CdZ"
这也有效，使用：interaction
library(stringr)
str_extract_all(x,"(?<=\\[).+?(?=\\])", simplify = TRUE) |>
str_split("") |>
interaction(sep = "") |> levels()
# [1] "AaX" "BaX" "CaX" "AbX" "BbX" "CbX" "AcX" "BcX" "CcX" "AdX" "BdX" "CdX" "AaY" "BaY" "CaY" "AbY" "BbY" "CbY" "AcY" "BcY"
#[21] "CcY" "AdY" "BdY" "CdY" "AaZ" "BaZ" "CaZ" "AbZ" "BbZ" "CbZ" "AcZ" "BcZ" "CcZ" "AdZ" "BdZ" "CdZ"
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