manipulate ruby hashes to generate data series

Question

I have hash from code like this below

{"Jan 2016"=>4649, "Feb 2016"=>3945, "Mar 2016"=>4870, "Apr 2016"=>4872,
"May 2016"=>6494, "Jun 2016"=>4981, "Jul 2016"=>9949, "Aug 2016"=>4842,
"Sep 2016"=>5820, "Oct 2016"=>4934, "Nov 2016"=>4136, "Dec 2016"=>8856,
"Jan 2017"=>3762, "Feb 2017"=>3261, "Mar 2017"=>2185, "Apr 2017"=>702}

this hash generated from code

@bookings.group_by_month(:check_in_date, format: "%b %Y").sum(:total_night)

I'm using this code to generate chart with chartkick, I would like to group it quarterly to generate data series so I can give each series with different color,

Expected output is

[
  {name: "Q1",data: {"Jan 2016"=>4649, "Feb 2016"=>3945, "Mar 2016"=>4870}},
  {name: "Q2",data: {"Apr 2016"=>4872, "May 2016"=>6494, "Jun 2016"=>4981}}
  …
]

Answer 1

a.group_by { |k, v| [Date.parse(k).year, ((Date.parse(k).month - 1) / 3) + 1] }
 .map { |k, v| { quarter: k, data: v.to_h} }
# [
#   {:quarter=>[2016, 1], :data=>{"Jan 2016"=>4649, "Feb 2016"=>3945, "Mar 2016"=>4870}},
#   {:quarter=>[2016, 2], :data=>{"Apr 2016"=>4872, "May 2016"=>6494, "Jun 2016"=>4981}},
#   {:quarter=>[2016, 3], :data=>{"Jul 2016"=>9949, "Aug 2016"=>4842, "Sep 2016"=>5820}},
#   {:quarter=>[2016, 4], :data=>{"Oct 2016"=>4934, "Nov 2016"=>4136, "Dec 2016"=>8856}},
#   {:quarter=>[2017, 1], :data=>{"Jan 2017"=>3762, "Feb 2017"=>3261, "Mar 2017"=>2185}},
#   {:quarter=>[2017, 2], :data=>{"Apr 2017"=>702}}
# ]