R：拆分字符列并创建两个新的

Question

R用户

我有一个与此相似的数据框：

a <- c("John, 3 years") 
b <- c("Mokobe, 11 years")
c <- c("Ivan")
df <- rbind(a,b,c)
df
  [,1]              
a "John, 3 years"   
b "Mokobe, 11 years"
c "Ivan" 

我应该使用哪个函数在逗号后分割列以获取：

df
[,1]    [,2]
John    3 years
Mokobe  11 years
Ivan    NA

Answer 1

我们可以通过定界符进行strsplit ,然后在末尾用NA填充后rbind list元素，以使每个list元素的length相同

lst <- strsplit(df[,1], ", ")
do.call(rbind, lapply(lst, `length<-`, max(lengths(lst))))
#   [,1]     [,2]      
#a "John"   "3 years" 
#b "Mokobe" "11 years"
#c "Ivan"   NA       

Answer 2

与提迪尔图书馆：

library(tidyr)
df <- as.data.frame(rbind(a,b,c), stringsAsFactors=F)
separate(df, V1, c("name", "age"),sep = ",")

Answer 3

只需通过read.csv使用fill=TRUE和header=FALSE直接读取数据。 您可以决定通过as.matrix()将其更改为矩阵

    read.csv(text=df,fill=T,header=F,na.strings = "")
      V1        V2
1   John   3 years
2 Mokobe  11 years
3   Ivan      <NA>   

转向矩阵。 虽然没有必要

as.matrix(read.csv(text=df,fill=1,h=0,na.strings = ""))
     V1       V2         
[1,] "John"   " 3 years" 
[2,] "Mokobe" " 11 years"
[3,] "Ivan"   NA   

Answer 4

# This should work
library(stringr)

a <- c("John, 3 years") 
b <- c("Mokobe, 11 years")
c <- c("Ivan")
df<- rbind(a,b,c)

df<- str_split_fixed(df, ",", 2)