如何将混合日期格式的变量转换为一种格式？ [英] How to convert variable with mixed date formats to one format?

问题描述

我的数据框示例：

                date
1   25 February 1987
2     20 August 1974
3     9 October 1984
4     18 August 1992
5  19 September 1995
6          16-Oct-63
7          30-Sep-65
8        22 Jan 2008
9         13-11-1961
10    18 August 1987
11         15-Sep-70
12    5 October 1994
13   5 December 1984
14          03/23/87
15    30 August 1988
16        26-10-1993
17    22 August 1989
18         13-Sep-97

我有一个很大的数据框，其中的日期变量具有多种日期格式。变量中的大多数格式如上所示-还有一些非常罕见的其他格式。之所以存在多种格式，是因为数据是从各个使用不同格式的网站中收集的。

I have a large dataframe with a date variable that has multiple formats for dates. Most of the formats in the variable are shown above- there are a couple of very rare others too. The reason why there are multiple formats is that the data were pulled together from various websites that each used different formats.

我尝试使用简单的转换方法，例如

I have tried using straightforward conversions e.g.

strftime(mydf$date,"%d/%m/%Y")

，但是如果有多种格式，则这种转换将无法进行。我不想诉诸于多种gsub类型编辑。我想知道是否缺少更简单的解决方案？

but these sorts of conversion will not work if there are multiple formats. I don't want to resort to multiple gsub type editing. I was wondering if I am missing a more simple solution?

例如代码：

    structure(list(date = structure(c(12L, 8L, 18L, 6L, 7L, 4L, 14L, 
10L, 1L, 5L, 3L, 17L, 16L, 11L, 15L, 13L, 9L, 2L), .Label = c("13-11-1961", 
"13-Sep-97", "15-Sep-70", "16-Oct-63", "18 August 1987", "18 August 1992", 
"19 September 1995", "20 August 1974", "22 August 1989", "22 Jan 2008", 
"03/23/87", "25 February 1987", "26-10-1993", "30-Sep-65", "30 August 1988", 
"5 December 1984", "5 October 1994", "9 October 1984"), class = "factor")), .Names = "date", row.names = c(NA, 
-18L), class = "data.frame")

推荐答案

您可以在<$ c包中尝试 parse_date_time $ c> lubridate 使用 orders 参数允许用户指定几种格式顺序来处理不同的日期时间字符表示形式。像...

You may try parse_date_time in package lubridate which "allows the user to specify several format-orders to handle heterogeneous date-time character representations" using the orders argument. Something like...

library(lubridate)
parse_date_time(x = df$date,
                orders = c("d m y", "d B Y", "m/d/y"),
                locale = "eng")

...应该能够处理大多数格式。请注意， b / B 格式对区域设置敏感。

...should be able to handle most of your formats. Please note that b/B formats are locale sensitive.

订单中可以使用的其他日期时间格式在的详细信息部分中列出了吗？ strptime 。

Other date-time formats which can be used in orders are listed in the Details section in ?strptime.

这篇关于如何将混合日期格式的变量转换为一种格式？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！