Nicely formatting output to console, specifying number of tabs

Question

I am generating a script that is outputting information to the console. The information is some kind of statistic with a value. So much like a hash.

So one value\'s

Answer 1

I wrote a thing

• Automatically detects column widths
• Spaces with spaces
• Array of arrays [[],[],...] or array of hashes [{},{},...]

• Does not detect columns too wide for console window

  lists = [ [ 123, "SDLKFJSLDKFJSLDKFJLSDKJF" ], [ 123456, "ffff" ], ]

array_maxes

def array_maxes(lists)
  lists.reduce([]) do |maxes, list|
    list.each_with_index do |value, index|
      maxes[index] = [(maxes[index] || 0), value.to_s.length].max
    end
    maxes
  end
end

array_maxes(lists)
# => [6, 24]

puts_arrays_columns

def puts_arrays_columns(lists)
  maxes = array_maxes(hashes)
  lists.each do |list|
    list.each_with_index do |value, index|
      print " #{value.to_s.rjust(maxes[index])},"
    end
    puts
  end
end

puts_arrays_columns(lists)

# Output:
#     123, SDLKFJSLDKFJSLDKFJLSDKJF,
#  123456,                     ffff,

and another thing

hashes = [
  { "id" => 123,    "name" => "SDLKFJSLDKFJSLDKFJLSDKJF" },
  { "id" => 123456, "name" => "ffff" },
]

hash_maxes

def hash_maxes(hashes)
  hashes.reduce({}) do |maxes, hash|
    hash.keys.each do |key|
      maxes[key] = [(maxes[key] || 0), key.to_s.length].max
      maxes[key] = [(maxes[key] || 0), hash[key].to_s.length].max
    end
    maxes
  end
end

hash_maxes(hashes)
# => {"id"=>6, "name"=>24}

puts_hashes_columns

def puts_hashes_columns(hashes)
  maxes = hash_maxes(hashes)

  return if hashes.empty?

  # Headers
  hashes.first.each do |key, value|
    print " #{key.to_s.rjust(maxes[key])},"
  end
  puts

  hashes.each do |hash|
    hash.each do |key, value|
      print " #{value.to_s.rjust(maxes[key])},"
    end
    puts
  end

end

puts_hashes_columns(hashes)

# Output:
#      id,                     name,
#     123, SDLKFJSLDKFJSLDKFJLSDKJF,
#  123456,                     ffff,

Edit: Fixes hash keys considered in the length.

hashes = [
  { id: 123,    name: "DLKFJSDLKFJSLDKFJSDF", asdfasdf: :a  },
  { id: 123456, name: "ffff",                 asdfasdf: :ab },
]

hash_maxes(hashes)
# => {:id=>6, :name=>20, :asdfasdf=>8}

Want to whitelist columns columns?

hashes.map{ |h| h.slice(:id, :name) }
# => [
#  { id: 123,    name: "DLKFJSDLKFJSLDKFJSDF" },
#  { id: 123456, name: "ffff"                 },
#]