def zip_hash(col1, col2)
      col1.zip(col2).inject({}) { |r, i| r[i[0]] = i[1]; r }
    end
def zip_hash(col1, col2)
      col1.zip(col2).inject({}) { |r, i| r[i[0]] = i[1]; r }
    end
Returns a hash using col1 as keys and col2 as values.

 @example zip_hash([:name, :age, :sex], ['Earl', 30, 'male'])
   => { :age => 30, :name => "Earl", :sex => "male" }

 @param [Array] col1
   Containing the keys.

 @param [Array] col2
   Values for hash.

 @return [Hash]