Clever Ruby Tricks

clever.rb

# Shortcut for Dir Globs
Dir["data_sets/*.csv"].each do |filepath|
  process_data_set(filepath)
end

# ARGF an IO object that wraps around all commandline paths
ARGF.readlines.select do |line|
  line.start_with?("A")
end.each do |line|
  puts line
end

# inject on a hash to get the key and value separate
attributes = {:id => :integer, :amount => :float}

attirbutes.inject([]) do |list, pair| #normally you just get the object being reduced into and a key/value pair
  key, value = pair
  # do something
end


attirbutes.inject([]) do |list, (key, value)| #you can get them separately like this
  # do something
end