更改R中时间和日期的格式

Question

我正在使用 R 处理 Twitter 数据，我有这样的日期和时间列“10/19/2018 23:00”，“10/19/2018 23:01”， “2018 年 10 月 19 日 23:02”，“2018 年 10 月 19 日 19:45”。我想将格式更改为没有日期，时间也没有分钟，例如 23 小时的任何时间我需要它只在 23 没有分钟。
这是列的示例：

created
10/19/2018 23:29
10/19/2018 23:29
10/19/2018 23:29
10/19/2018 23:29
10/19/2018 23:29
10/19/2018 23:29
10/19/2018 23:29
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10/19/2018 15:32
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10/19/2018 15:32

我需要它像这样 15:00 23:00 16:00

希望你能理解我你能帮我做一下吗，谢谢。

Answer 1

我们可以使用sub

sub('.*\s(.{2}).*', '\1:00', df1$created)
#[1] "23:00" "23:00" "23:00" "23:00"

或转换为 DateTime class 然后用 format

提取组件

format(as.POSIXct(df1$created, format = "%m/%d/%Y %H:%M"), "%H:00")
#[1] "23:00" "23:00" "23:00" "23:00"

数据

df1 <- data.frame(created = c('10/19/2018 23:29',
  '10/19/2018 23:29', '10/19/2018 23:29', 
  '10/19/2018 23:29'), stringsAsFactors = FALSE)

Answer 2

x<-
c("10/19/2018 23:29", "10/19/2018 23:29", "10/19/2018 23:29", "10/19/2018 23:29")

paste0(unlist(regmatches(x, gregexpr("(?<=\s)\d{2}(?=:\d{2})", x, perl = T))), ":00")

#[1] "23:00" "23:00" "23:00" "23:00"

更改R中时间和日期的格式

change the format of time and date in R

r

sentiment-analysis

数据