如何从POSIXct类型timestamp列提取年月生成指定格式新列

现有数据集pr5915包含POSIXct类型的timestamp列，需要新增一列Date，格式为英文全称月份-年份后两位（例如：December-20）。

原始数据集 #

pr5915<-structure(list(activity = c("Forged Wire, Medium (Sport)", "Forged Wire, Medium (Sport)", 
"Forged Wire, Medium (Sport)", "Forged Wire, Medium (Sport)", 
"BBH-1&2", "Forged Wire, Medium (Sport)", "TCE Cleaning", "SOLO Oil", 
"Tempering", "TCE Cleaning", "Tempering", "BBH-1&2", "BBH-1&2", 
"TCE Cleaning", "Tempering"), timestamp = structure(c(-62042010952, 
-62010323872, -61884118792, -61821087232, -61821025132, -61789534972, 
-61789520332, -61789494952, -61757940232, -61757925652, -61757895952, 
-61694827552, -61694808292, -61663337152, -61663307452), tzone = "Europe/Istanbul", class = c("POSIXct", 
"POSIXt"))), row.names = c(NA, -15L), class = c("eventlog", "log", 
"tbl_df", "tbl", "data.frame"), case_id = "case_id", activity_id = "activity", activity_instance_id = "action", lifecycle_id = "lifecycle", resource_id = "resource", timestamp = "timestamp")

实现方案 #

1. Base R 方式 #

使用strftime()函数直接格式化时间戳，格式符说明：

• %B：英文全称月份（如December）
• %y：年份后两位（如20）

pr5915$Date <- strftime(pr5915$timestamp, format = "%B-%y")

2. Tidyverse/dplyr 方式 #

如果使用tidyverse工具链，管道式操作更简洁：

library(dplyr)

pr5915 <- pr5915 %>%
  mutate(Date = strftime(timestamp, format = "%B-%y"))

处理后的数据集示例（截取前3行） #

structure(list(activity = c("Forged Wire, Medium (Sport)", "Forged Wire, Medium (Sport)", 
"Forged Wire, Medium (Sport)"), timestamp = structure(c(-62042010952, 
-62010323872, -61884118792), tzone = "Europe/Istanbul", class = c("POSIXct", 
"POSIXt")), Date = c("January-00", "February-00", "May-00")), row.names = c(NA, 
-3L), class = c("eventlog", "log", "tbl_df", "tbl", "data.frame"), case_id = "case_id", activity_id = "activity", activity_instance_id = "action", lifecycle_id = "lifecycle", resource_id = "resource", timestamp = "timestamp")

内容的提问来源于stack exchange，提问作者firmo23