ruby-on-rails - 在哈希中获取空月份

Question

我有 Month->Value 的散列

{"Apr 2016"=>6, "Aug 2016"=>9, "Jan 2017"=>11, "Apr 2017"=>6, "May 2017"=>9, "Jun 2017"=>1, "Jul 2017"=>9}

我想知道在第一个值和最后一个值之间获取所有空月份的最佳方法是什么

我想要这样的东西

{"Apr 2016"=>6, May 2016=>0, Jun 2016=>0 .... "Aug 2016"=>9, "Sep 2016" => 0 "Jan 2017"=>11, "Apr 2017"=>6, "May 2017"=>9, "Jun 2017"=>1, "Jul 2017"=>9}

Answer 1

这是另一种方法，使用 each_with_object:

def add_months(dates)
  min, max = dates.keys.map { |date| Date.parse(date) }.minmax
  range    = (min..max).map { |date| date.strftime("%b %Y") }.uniq

  range.each_with_object({}) { |date, result| result[date] = dates[date] || 0 }
end

输出:

dates = {"Apr 2016"=>6, "Aug 2016"=>9, "Jan 2017"=>11, "Apr 2017"=>6, "May 2017"=>9, "Jun 2017"=>1, "Jul 2017"=>9}

add_months(dates)
#=> {
#     "Apr 2016"=>6,
#     "May 2016"=>0,
#     "Jun 2016"=>0,
#     "Jul 2016"=>0,
#     "Aug 2016"=>9,
#     "Sep 2016"=>0,
#     "Oct 2016"=>0,
#     "Nov 2016"=>0,
#     "Dec 2016"=>0,
#     "Jan 2017"=>11,
#     "Feb 2017"=>0,
#     "Mar 2017"=>0,
#     "Apr 2017"=>6,
#     "May 2017"=>9,
#     "Jun 2017"=>1,
#     "Jul 2017"=>9
#   }