R-基于模式提取字符串

Question

我有一个矢量数据(这是数据框中的一列)：

 [1] "Tue 12-14 (w1-6, CLB 6)"           "Mon 18-20 (w1-6, ColomboThC)"      "Thu 14-16 (w1-6,7-9,10-12, CLB 8)"
 [4] "Fri 13 (w2-9,10-13, Law 388)"      "Fri 14 (w2-9,10-13, Sqhouse206)"   "Fri 15 (w2-9,10-13, Sqhouse115)"  
 [7] "Thu 17 (w2-9,10-13, Block G16)"    "Thu 18 (w2-9,10-13, Block G16)"    "Mon 10 (w2-9,10-13, AinswthG01)"  
[10] "Mon 11 (w2-9,10-13, Sqhouse203)"   "Mon 12 (w2-9,10-13, Sqhouse206)"   "Mon 13 (w2-9,10-13, BUS 114)"     
[13] "Mon 16 (w2-9,10-13, Gold G03)"     "Mon 17 (w2-9,10-13, Quad G047)"    "Mon 20 (w2-9,10-13, Col LG02)"    
[16] "Tue 17 (w2-9,10-13, Quad 1001)"    "Tue 18 (w2-9,10-13, Quad 1001)"    "Tue 19 (w2-9,10-13, Quad 1001)"   
[19] "Tue 20 (w2-9,10-13)"               "Wed 10 (w2-9,10-13, Quad 1046)"    "Wed 11 (w2-9,10-13, Quad 1046)"   
[22] "Wed 12 (w2-9,10-13, Quad 1046)"    "Wed 13 (w2-9,10-13, Quad G046)"

我想根据模式提取字符串，因此，作为示例，向量的第一个元素的预期输出为：

"Tue" "12-14"  "1-6" "CLB 6"

第三个元素的输出示例如下：

 "Thu" "14-16" c("1-6","7-9","10-12") "CLB 8"

其中c("1-6","7-9","10-12")是一个列表。

(请注意，其中的每一个都将作为新列附加到我的数据框中。)

我正在考虑使用gsub来提取字符串的每一部分。还有没有其他我可以使用的函数？

任何建议都是非常感谢的:)

Answer 1

我们可以尝试使用tidyverse中的函数

library(tidyverse)
str_split_fixed(vec, pattern = " ", n = 3) %>% 
  as.data.frame() %>%
  mutate(V3 = str_sub(V3,3,-2)) %>%
  separate(V3, c("V3", "V4"), sep = ", ")

代码编写如下：

1. 通过一个空格将向量vec拆分为3列，并将其强制为第三列中的dataframe.
2. Extract字符串，以排除左方括号和右方括号以及“w”。
3. 使用", ".

分隔第三列

输出示例：

   V1    V2            V3         V4
1 Tue 12-14           1-6      CLB 6
2 Mon 18-20           1-6 ColomboThC
3 Thu 14-16 1-6,7-9,10-12      CLB 8

Answer 2

在结尾处的注释中使用输入x：

将每个字符串中的第一个空格替换为分号，将下一个空格及其后面的两个字符替换为分号，将下一次出现的逗号替换为最后一个在数据框中使用逗号的character

• read将第3列的字段拆分为使用逗号的字符向量列表--如果您希望字符串而不是作为第3列

列出，请省略此步骤

它只使用单独的简单步骤，没有包。

y <- x
y <- sub(" ", ";", y)
y <- sub(" ..", ";", y)
y <- sub(", ", ";", y)
y <- sub(".$", "", y)
DF <- read.table(text = y, sep = ";", as.is = TRUE, fill = NA)
DF[[3]] <- strsplit(DF[[3]], ",")

给予：

> DF
    V1    V2              V3         V4
1  Tue 12-14             1-6      CLB 6
2  Mon 18-20             1-6 ColomboThC
3  Thu 14-16 1-6, 7-9, 10-12      CLB 8
4  Fri    13      2-9, 10-13    Law 388
5  Fri    14      2-9, 10-13 Sqhouse206
6  Fri    15      2-9, 10-13 Sqhouse115
7  Thu    17      2-9, 10-13  Block G16
8  Thu    18      2-9, 10-13  Block G16
9  Mon    10      2-9, 10-13 AinswthG01
10 Mon    11      2-9, 10-13 Sqhouse203
11 Mon    12      2-9, 10-13 Sqhouse206
12 Mon    13      2-9, 10-13    BUS 114
13 Mon    16      2-9, 10-13   Gold G03
14 Mon    17      2-9, 10-13  Quad G047
15 Mon    20      2-9, 10-13   Col LG02
16 Tue    17      2-9, 10-13  Quad 1001
17 Tue    18      2-9, 10-13  Quad 1001
18 Tue    19      2-9, 10-13  Quad 1001
19 Tue    20      2-9, 10-13           
20 Wed    10      2-9, 10-13  Quad 1046
21 Wed    11      2-9, 10-13  Quad 1046

可以用这一行代码替换前4行代码，在这种情况下，总共只有4行代码。

y <- Reduce(function(x, pat) sub(pat, ";", x), init = x, c(" ", " ..", ", "))

注意：可复制形式的输入x为：

x <- c("Tue 12-14 (w1-6, CLB 6)", "Mon 18-20 (w1-6, ColomboThC)", 
"Thu 14-16 (w1-6,7-9,10-12, CLB 8)", "Fri 13 (w2-9,10-13, Law 388)", 
"Fri 14 (w2-9,10-13, Sqhouse206)", "Fri 15 (w2-9,10-13, Sqhouse115)", 
"Thu 17 (w2-9,10-13, Block G16)", "Thu 18 (w2-9,10-13, Block G16)", 
"Mon 10 (w2-9,10-13, AinswthG01)", "Mon 11 (w2-9,10-13, Sqhouse203)", 
"Mon 12 (w2-9,10-13, Sqhouse206)", "Mon 13 (w2-9,10-13, BUS 114)", 
"Mon 16 (w2-9,10-13, Gold G03)", "Mon 17 (w2-9,10-13, Quad G047)", 
"Mon 20 (w2-9,10-13, Col LG02)", "Tue 17 (w2-9,10-13, Quad 1001)", 
"Tue 18 (w2-9,10-13, Quad 1001)", "Tue 19 (w2-9,10-13, Quad 1001)", 
"Tue 20 (w2-9,10-13)", "Wed 10 (w2-9,10-13, Quad 1046)", "Wed 11 (w2-9,10-13, Quad 1046)", 
"Wed 12 (w2-9,10-13, Quad 1046)", "Wed 13 (w2-9,10-13, Quad G046)"

Answer 3

Base函数可以做的，你不需要导入任何其他的包。tidyverse是一个很好的工具，但是对于这个来说有点大了，

x=c("Thu 18 (w2-9,10-13, Block G16)","Mon 18-20 (w1-6, ColomboThC)")
do.call(rbind,lapply(x,function(i){
  y=strsplit(i,' \\(')[[1]]
  y[2]=gsub('\\)','',y[2])
  out1=strsplit(y[1],' ')[[1]]
  out2=strsplit(y[2],', ')[[1]]
  listpart=grepl('-',out2)
  do.call(cbind,c(out1,list(out2[listpart]),out2[!listpart]))
}))

输出将为：

         [,1]  [,2]    [,3]         [,4]        
[1,] "Thu" "18"    "w2-9,10-13" "Block G16" 
[2,] "Mon" "18-20" "w1-6"       "ColomboThC"