我想要将这列数据处理为只显示姓氏,如果该列中存在逗号,则需要删除逗号及其后面的内容。该列数据包含仅有姓氏和姓氏名字混合的情况。数据如下:
Last Name
Sample, A
Tester
Wilfred, Nancy
Day, Bobby Jean
Morris
您可以使用gsub()和一些正则表达式:
> x <- 'Day, Bobby Jean'
> gsub("(.*),.*", "\\1", x)
[1] "Day"
gsub(",.*", "", c("last only", "last, first"))
# [1] "last only" "last"
",.*"
的意思是:用空白替换逗号 (,) 及其后的所有字符 (.*), 即替换为空 ""
。
还可以尝试使用strsplit
函数:
string <- c("Sample, A", "Tester", "Wifred, Nancy", "Day, Bobby Jean", "Morris")
sapply(strsplit(string, ","), "[", 1)
#[1] "Sample" "Tester" "Wifred" "Day" "Morris"
str1 <- c("Sample, A", "Tester", "Wifred, Nancy", "Day, Bobby Jean", "Morris")
library(stringr)
str_extract(str1, perl('[A-Za-z]+(?=(,|\\b))'))
#[1] "Sample" "Tester" "Wifred" "Day" "Morris"
匹配字母[A-Za-z]+
并提取那些后面跟着,
或单词边界的字母。
这将会起作用
a <- read.delim("C:\\Desktop\\a.csv", row.names = NULL,header=TRUE,
stringsAsFactors=FALSE,sep=",")
a=as.matrix(a)
Data=str_replace_all(string=a,pattern="\\,.*$",replacement=" ")