如何在 R 中将字符串转换为日期

Question

有没有办法将下面的字符串转换为标准的 R 日期 class object？

Date_String = "19th January 2020"

任何指针表示赞赏。

Answer 1

Lubridate可以处理它：

> Date_String <- "19th January 2020"
> lubridate::dmy(Date_String)
[1] "2020-01-19"

Answer 2

在基础 R 中：

# Make sure your locale is English
Sys.getlocale() # can update with Sys.setlocale(LC_TIME = 'en_US.UTF-8')

# Remove "th", more generally the first sequence of lower-case letters
Date_String <- sub("[a-z]+", "", Date_String)
# Now specify the format for as.Date()
as.Date(Date_String, format = "%d %B %Y")
[1] "2020-01-19"

Answer 3

    Date_String <- "19th January 2020"

    # Using BASE R
    Date_String <- sub("st|nd|rd|th", "", Date_String)
    as.Date(Date_String, format = "%d %B %Y")
    #> [1] "2020-01-19"

    # Using Lubridate package
    lubridate::dmy(Date_String)
    #> [1] "2020-01-19"