require 'daru'

vector = Daru::Vector.new([2,4,5,51,5,16,2,5,3,2,1,5,2,5,2,1,56,234,6,21])
vector.where((vector.eq(5) | vector.eq(1)) & vector.mt(2))

df = Daru::DataFrame.new({
  a: [1,2,3,4,5,6]*100,
  b: ['a','b','c','d','e','f']*100,
  c: [11,22,33,44,55,66]*100
}, index: (1..600).to_a.shuffle)

df.where(df[:a].eq(2) | df[:c].eq(55))

vector.where(vector.eq(2).or(vector.eq(5)).and(vector.mt(2)))

left = Daru::DataFrame.new({
  :id   => [1,2,3,4],
  :name => ['Pirate', 'Monkey', 'Ninja', 'Spaghetti']
})
right = Daru::DataFrame.new({
  :id => [1,2,3,4],
  :name => ['Rutabaga', 'Pirate', 'Darth Vader', 'Ninja']
})
nil

left.join(right, on: [:name], how: :inner)

left.join(right, on: [:name], how: :left)

left.join(right, on: [:name], how: :right)

left.join(right, on: [:name], how: :outer)