How to sum values from an Array of objects - arrays

Question

I have a data structure in Ruby as below:
[["N1-Alb",
{'Sun, 05 Feb 2017'=>"",
'Mon, 06 Feb 2017'=>"",
'Tue, 07 Feb 2017'=>"",
'Wed, 08 Feb 2017'=>"0.25",
'Thu, 09 Feb 2017'=>"0.03",
'Fri, 10 Feb 2017'=>"",
'Sat, 11 Feb 2017'=>""}],
["N1-Cet",
{'Sun, 05 Feb 2017'=>"",
'Mon, 06 Feb 2017'=>"7.8",
'Tue, 07 Feb 2017'=>"",
'Wed, 08 Feb 2017'=>"0.00",
'Thu, 09 Feb 2017'=>"",
'Fri, 10 Feb 2017'=>"",
'Sat, 11 Feb 2017'=>""}],
["N3-Tju",
{'Sun, 05 Feb 2017'=>"",
'Mon, 06 Feb 2017'=>"",
'Tue, 07 Feb 2017'=>"",
'Wed, 08 Feb 2017'=>"3.15",
'Thu, 09 Feb 2017'=>"",
'Fri, 10 Feb 2017'=>"8.0",
'Sat, 11 Feb 2017'=>""}],
["N7-Mlp",
{'Sun, 05 Feb 2017'=>"",
'Mon, 06 Feb 2017'=>"",
'Tue, 07 Feb 2017'=>"5.01",
'Wed, 08 Feb 2017'=>"0.03",
'Thu, 09 Feb 2017'=>"",
'Fri, 10 Feb 2017'=>"",
'Sat, 11 Feb 2017'=>"4"}]]
How can I get sum for all Sundays, Mondays etc. up to Saturdays separately in to a Hash or an Array format?
The final hash should be:
result = { 'sun': '0',
'mon': '7.8',
'tue': '5.01',
'wed': '3.43',
'thu': '0.03',
'fri': '8.0',
'sat': '4' }

Answer 1

Try this:
days = [:mon, :tue, :wed, :thu, :fri, :sat, :sun]
result = your_hash.each_with_object({}) do |n, h|
n[1].each do |key, value|
h[days[key.cwday - 1]] = (h[days[key.cwday - 1]].to_f + value.to_f).to_s
end
end
I updated the code to be more concise, per your request. This code exploits the fact that nil.to_f == 0.0, which may upset some stomachs.