使用gsub创建统一的时间格式

时间：2015-06-07 03:44:13

标签： regex r datetime gsub

我正在尝试重新格式化当前为字符格式的时间。我想让它们变得均匀。现在他们看起来像这样：

INSERT INTO TestTable1 (FirstName, Email) VALUES (@FirstName, @Email)

我希望所有时间都采用这种格式：

下午1:00而不是下午1点 下午12:45而不是下午12:45:30

所以基本上HH：MM附加AM或PM

最终我想将时间从字符格式转换为POSIXct格式。但这只能通过统一的字符格式实现。更具体一点：作为一个例子，你如何使用 [1] "1:00PM" "1:10 PM" "1:10PM" "1:20 PM" "1:30 PM" "1:30PM" [7] "1:40 PM" "10:00AM" "10:10 AM" "10:10AM" "10:30 AM" "10:30AM" [13] "10:45 AM" "10:45AM" "10:50 AM" "10:50AM" "10AM" "11:00AM" [19] "11:10 AM" "11:10AM" "11:40 AM" "11:40AM" "11AM" "12:00PM" [25] "12:05 PM" "12:10 PM" "12:10PM" "12:25PM" "12:30 PM" "12:30PM" [31] "12:45 PM" "12:45:30 PM" "12:45PM" "12:50 PM" "12PM" "1PM" [37] "2:00PM" "2:10 PM" "2:10PM" "2:20PM" "2:30 PM" "2:30PM" [43] "2:35 PM" "2:45 PM" "2:45PM" "2:55 PM" "2PM" "3:00PM" [49] "3:05 PM" "3:10 PM" "3:10PM" "3:20 PM" "3:20PM" "3:25 PM" [55] "3:25PM" "3:30 PM" "3:35 PM" "3:35PM" "3:45 PM" "3:45PM" [61] "3PM" "4:00PM" "4:10 PM" "4:10PM" "4:30 PM" "4:30PM" [67] "4:35 PM" "4:35PM" "4PM" "5:00PM" "5:10 PM" "5:10PM" [73] "5:20 PM" "5:30 PM" "5:30PM" "5:35 PM" "5:35PM" "5:40 PM" [79] "5:40PM" "5:45 PM" "5:50 PM" "5:50PM" "6:00PM" "6:05PM" [85] "6:10 PM" "6:10PM" "6:15PM" "6:30 PM" "6:30PM" "6PM" [91] "7:00PM" "7:10 AM" "7:10 PM" "7:10AM" "7:10PM" "7:30PM" [97] "7:35 PM" "7:35PM" "7:45 PM" "7:45PM" "7AM" "7PM" [103] "8:00AM" "8:10 AM" "8:10AM" "8:25 PM" "8:25PM" "8:50 PM" [109] "8AM" "9:00AM" "9:10 AM" "9:10AM" "9:15 AM" "9:15AM" [115] "9:20 AM" "9:30 AM" "9:30AM" "9:35AM" "9:40 AM" "9:40AM" [121] "9:45 AM" "9:45AM" "9AM" 将“3PM”更改为“3:00 PM”，同样将“12:45:30 PM”更改为“12:45 PM”？

我很难绕过gsub中的一些正则表达式语法 - 特别是如何引用特定位置，比如字符串中的位置4。

1 个答案:

答案 0 :(得分：6)

我们为没有:即（上午10点，上午11点等）的元素创建索引（＆＃39; indx＆＃39;），使用sub我们更改格式（上午10:00，上午11:00等）。我们匹配前两位数字，后跟:，两位数字（\\d{2}），将其作为带括号的组捕获，匹配不是AM / PM（[^AMP]+）的字符，匹配作为AM / PM并选择作为第二个捕获组的字符，使用第一个和第二个捕获的组（\\1\\2）作为替换。现在，我们可以使用strsplit/sprintf在开头填0，以获取不具有两位数的元素。

indx <- !grepl(':', str1)
str1[indx] <- sub('(\\d+)(.*)', '\\1:00\\2', str1[indx])
str1 <- sub('(^\\d+:\\d{2})[^AMP]+([AMP])', '\\1\\2', str1)
sapply(strsplit(str1, ':'), function(x) paste(sprintf('%02d',
          as.numeric(x[1])), x[2], sep=":"))
#[1] "01:00PM" "01:10PM" "01:10PM" "01:20PM" "01:30PM" "01:30PM" "01:40PM"
#[8] "10:00AM" "10:10AM" "10:10AM" "10:30AM" "10:30AM" "10:45AM" "10:45AM"
#[15] "10:50AM" "10:50AM" "10:00AM" "11:00AM" "11:10AM" "11:10AM" "11:40AM"
#[22] "11:40AM" "11:00AM" "12:00PM" "12:05PM" "12:10PM" "12:10PM" "12:25PM"
#[29] "12:30PM" "12:30PM" "12:45PM" "12:45PM" "12:45PM" "12:50PM" "12:00PM"
#[36] "01:00PM" "02:00PM" "02:10PM" "02:10PM" "02:20PM" "02:30PM" "02:30PM"
#[43] "02:35PM" "02:45PM" "02:45PM" "02:55PM" "02:00PM" "03:00PM" "03:05PM"
#[50] "03:10PM" "03:10PM" "03:20PM" "03:20PM" "03:25PM" "03:25PM" "03:30PM"
#[57] "03:35PM" "03:35PM" "03:45PM" "03:45PM" "03:00PM" "04:00PM" "04:10PM"
#[64] "04:10PM" "04:30PM" "04:30PM" "04:35PM" "04:35PM" "04:00PM" "05:00PM"
#[71] "05:10PM" "05:10PM" "05:20PM" "05:30PM" "05:30PM" "05:35PM" "05:35PM"
#[78] "05:40PM" "05:40PM" "05:45PM" "05:50PM" "05:50PM" "06:00PM" "06:05PM"
#[85] "06:10PM" "06:10PM" "06:15PM" "06:30PM" "06:30PM" "06:00PM" "07:00PM"
#[92] "07:10AM" "07:10PM" "07:10AM" "07:10PM" "07:30PM" "07:35PM" "07:35PM"
#[99] "07:45PM" "07:45PM" "07:00AM" "07:00PM" "08:00AM" "08:10AM" "08:10AM"
#[106] "08:25PM" "08:25PM" "08:50PM" "08:00AM" "09:00AM" "09:10AM" "09:10AM"
#[113] "09:15AM" "09:15AM" "09:20AM" "09:30AM" "09:30AM" "09:35AM" "09:40AM"
#[120] "09:40AM" "09:45AM" "09:45AM" "09:00AM"

或者代替strsplit和sapply，我们可以使用format 

 sub('^ ', '0', format(str1, justify='right'))

或者

 library(stringr)
 str_pad(str1, pad='0', width=7)

或者我们可以使用lubridate包，其中包含多个格式字符串的选项

 library(lubridate)
 paste0(format(parse_date_time(str1, orders=guess_formats(gsub('[APM]', 
   '', str1), c('hm', 'hms', 'h'))), '%H:%M'), sub('[^AMP]+', '', str1))
 #[1] "01:00PM" "01:10PM" "01:10PM" "01:20PM" "01:30PM" "01:30PM" "01:40PM"
 #[8] "10:00AM" "10:10AM" "10:10AM" "10:30AM" "10:30AM" "10:45AM" "10:45AM"
 #[15] "10:50AM" "10:50AM" "10:00AM" "11:00AM" "11:10AM" "11:10AM" "11:40AM"
 #[22] "11:40AM" "11:00AM" "12:00PM" "12:05PM" "12:10PM" "12:10PM" "12:25PM"
 #[29] "12:30PM" "12:30PM" "12:45PM" "12:45PM" "12:45PM" "12:50PM" "12:00PM"
 #[36] "01:00PM" "02:00PM" "02:10PM" "02:10PM" "02:20PM" "02:30PM" "02:30PM"
 #[43] "02:35PM" "02:45PM" "02:45PM" "02:55PM" "02:00PM" "03:00PM" "03:05PM"
 #[50] "03:10PM" "03:10PM" "03:20PM" "03:20PM" "03:25PM" "03:25PM" "03:30PM"
 #[57] "03:35PM" "03:35PM" "03:45PM" "03:45PM" "03:00PM" "04:00PM" "04:10PM"
 #[64] "04:10PM" "04:30PM" "04:30PM" "04:35PM" "04:35PM" "04:00PM" "05:00PM"
 #[71] "05:10PM" "05:10PM" "05:20PM" "05:30PM" "05:30PM" "05:35PM" "05:35PM"
 #[78] "05:40PM" "05:40PM" "05:45PM" "05:50PM" "05:50PM" "06:00PM" "06:05PM"
 #[85] "06:10PM" "06:10PM" "06:15PM" "06:30PM" "06:30PM" "06:00PM" "07:00PM"
 #[92] "07:10AM" "07:10PM" "07:10AM" "07:10PM" "07:30PM" "07:35PM" "07:35PM"
 #[99] "07:45PM" "07:45PM" "07:00AM" "07:00PM" "08:00AM" "08:10AM" "08:10AM"
 #[106] "08:25PM" "08:25PM" "08:50PM" "08:00AM" "09:00AM" "09:10AM" "09:10AM"
 #[113] "09:15AM" "09:15AM" "09:20AM" "09:30AM" "09:30AM" "09:35AM" "09:40AM"
 #[120] "09:40AM" "09:45AM" "09:45AM" "09:00AM"

数据

str1 <- c("1:00PM", "1:10 PM", "1:10PM", "1:20 PM", "1:30 PM", "1:30PM", 
"1:40 PM", "10:00AM", "10:10 AM", "10:10AM", "10:30 AM", "10:30AM", 
"10:45 AM", "10:45AM", "10:50 AM", "10:50AM", "10AM", "11:00AM", 
"11:10 AM", "11:10AM", "11:40 AM", "11:40AM", "11AM", "12:00PM", 
"12:05 PM", "12:10 PM", "12:10PM", "12:25PM", "12:30 PM", "12:30PM", 
"12:45 PM", "12:45:30 PM", "12:45PM", "12:50 PM", "12PM", "1PM", 
"2:00PM", "2:10 PM", "2:10PM", "2:20PM", "2:30 PM", "2:30PM", 
"2:35 PM", "2:45 PM", "2:45PM", "2:55 PM", "2PM", "3:00PM", "3:05 PM", 
"3:10 PM", "3:10PM", "3:20 PM", "3:20PM", "3:25 PM", "3:25PM", 
"3:30 PM", "3:35 PM", "3:35PM", "3:45 PM", "3:45PM", "3PM", "4:00PM", 
"4:10 PM", "4:10PM", "4:30 PM", "4:30PM", "4:35 PM", "4:35PM", 
"4PM", "5:00PM", "5:10 PM", "5:10PM", "5:20 PM", "5:30 PM", "5:30PM", 
"5:35 PM", "5:35PM", "5:40 PM", "5:40PM", "5:45 PM", "5:50 PM", 
"5:50PM", "6:00PM", "6:05PM", "6:10 PM", "6:10PM", "6:15PM", 
"6:30 PM", "6:30PM", "6PM", "7:00PM", "7:10 AM", "7:10 PM", "7:10AM", 
"7:10PM", "7:30PM", "7:35 PM", "7:35PM", "7:45 PM", "7:45PM", 
"7AM", "7PM", "8:00AM", "8:10 AM", "8:10AM", "8:25 PM", "8:25PM", 
"8:50 PM", "8AM", "9:00AM", "9:10 AM", "9:10AM", "9:15 AM", "9:15AM", 
"9:20 AM", "9:30 AM", "9:30AM", "9:35AM", "9:40 AM", "9:40AM", 
"9:45 AM", "9:45AM", "9AM")
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