删除字符后但存在相同字符的所有内容

Question

在这样的数据框中：

df <- data.frame(id=c(1,2,3,4), text = c("word1","word2","word3","word4"), ts = c("something1,here,other","something2,here,other","something5,here,other","something4,here,other")

我只想保留ts列中第一个逗号之前的内容，并删除之后的内容。像这样的结果：

df <- data.frame(id=c(1,2,3,4), text = c("word1","word2","word3","word4"), ts = c("something1","something2","something5","something4")

我试过了，但是不适合：

df$ts <- gsub(",","",df$ts)

我该如何进行？

Answer 1

你非常亲密... 使用,.*作为模式，替换逗号，并替换第一个逗号之后的所有内容（即.*部分）。

df$ts <- gsub( ",.*", "", df$ts )

#   id  text         ts
# 1  1 word1 something1
# 2  2 word2 something2
# 3  3 word3 something5
# 4  4 word4 something4            

详细了解正则表达式：http://stat545.com/block022_regular-expression.html