Question

我有一个如下所示的字符串：log/archive/2016-12-21.zip，我需要提取日期部分。

到目前为止，我已尝试过这些解决方案：

1) ["log/archive/2016-12-21.zip"].map{|i|i[/\d{4}-\d{2}-\d{2}/]}.first 
2) "log/archive/2016-12-21.zip".to_date
3) "log/archive/2016-12-21.zip".split("/").last.split(".").first

有更好的方法吗？

Answer 1

您可以使用File.basename传递扩展程序：

File.basename("log/archive/2016-12-21.zip", ".zip")
# => "2016-12-21"

如果您希望该值为Date，只需使用Date.parse将字符串转换为“日期”。

require 'date'
Date.parse(File.basename("log/archive/2016-12-21.zip", ".zip"))

Answer 2

drv->probe()

如果您只想要日期字符串而不是日期对象，请按以下方式更改方法。

require 'date'

def pull_dates(str)
  str.split(/[\/.]/).map { |s| Date.strptime(s, '%Y-%m-%d') rescue nil }.compact
end

pull_dates "log/archive/2016-12-21.zip"
  #=> [#<Date: 2016-12-21 ((2457744j,0s,0n),+0s,2299161j)>]
pull_dates "log/2016-12-21/archive.zip"
  #=> [#<Date: 2016-12-21 ((2457744j,0s,0n),+0s,2299161j)>]
pull_dates "log/2016-12-21/2016-12-22.zip"
  #=> [#<Date: 2016-12-21 ((2457744j,0s,0n),+0s,2299161j)>,
  #    #<Date: 2016-12-22 ((2457745j,0s,0n),+0s,2299161j)>] 
pull_dates "log/2016-12-21/2016-12-32.zip"
  #=> [#<Date: 2016-12-21 ((2457744j,0s,0n),+0s,2299161j)>]
pull_dates "log/archive/2016A-12-21.zip"
  #=> []
pull_dates "log/archive/2016/12/21.zip"
  #=> []

Answer 3

这个正则表达式应该涵盖大多数情况。它允许年，月，日之间的可选非数字：

require 'date'

def extract_date(filename)
  if filename =~ /((?:19|20)\d{2})\D?(\d{2})\D?(\d{2})/ then
    year, month, day = $1.to_i, $2.to_i, $3.to_i
    # Do something with year, month, day, or just leave it like this to return an array : [2016, 12, 21]
    # Date.new(year, month, day)
  end
end

p extract_date("log/archive/2016-12-21.zip")
p extract_date("log/archive/2016.12.21.zip")
p extract_date("log/archive/2016:12:21.zip")
p extract_date("log/archive/2016_12_21.zip")
p extract_date("log/archive/20161221.zip")
p extract_date("log/archive/2016/12/21.zip")
p extract_date("log/archive/2016/12/21")
#=> Every example returns [2016, 12, 21]

Answer 4

请试试这个

"log/archive/2016-12-21.zip".scan(/\d{4}-\d{2}-\d{2}/).pop
=> "2016-12-21"

如果日期格式无效，则返回nil。

实施例： -

"log/archive/20-12-21.zip".scan(/\d{4}-\d{2}-\d{2}/).pop
             ^^
=> nil

希望它有所帮助。

从文件路径字符串中提取日期部分

4 个答案: