提问人：Mando 提问时间：9/8/2023 最后编辑：Mando 更新时间：9/8/2023 访问量：36
在 R 中将两个前缀替换为 nothing
replace two prefix with nothing in R
问：
我想删除前缀为 2023 或 2022 的列。
vec = c("2022-10-16", "2022-10-23", "2022-10-30", "2022-11-06", "2023-01-01", "2023-01-15")
我知道这是不正确的，但有类似的东西吗？
gsub("2023" | "2022", "", vec)
答：
0赞
Mark
9/8/2023
#1
df <- data.frame(
vec = c("2022-10-16", "2022-10-23", "2022-10-30", "2022-11-06", "2023-01-01", "2023-01-15"),
value = 1:6)
# if you meant actually meant remove the rows that start with 2023 or 2022, then you can use this:
df[!grepl("^(202[23])", df$vec),]
# or using dplyr:
df %>% dplyr::filter(!grepl("^(202[23])", vec))
# if you wanted to just remove the year from the date, then you can use this:
df$vec <- gsub("^202[23]", "", df$vec)
# or with tidyverse
library(tidyverse)
df |> mutate(vec = str_remove(vec, "^202[23]"))
评论
grep("202[23]", vec, value = TRUE, invert= TRUE)