parent -> Pathname
[permalink][rdoc]self の親ディレクトリを指す新しい Pathname オブジェクトを返します。
require "pathname"
path = Pathname("/usr")
path # => #<Pathname:/usr>
path.parent # => #<Pathname:/>
require "pathname"
path = Pathname("foo/bar")
path.parent # => #<Pathname:foo>
path.parent.parent # => #<Pathname:.>
path.parent.parent.parent # => #<Pathname:..>