Class: Polars::Enum

Inherits:
DataType show all
Defined in:
lib/polars/data_types.rb

Overview

A fixed set categorical encoding of a set of strings.

NOTE: this is an experimental work-in-progress feature and may not work as expected.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(categories) ⇒ Enum

Returns a new instance of Enum.



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# File 'lib/polars/data_types.rb', line 368

def initialize(categories)
  if !categories.is_a?(Series)
    categories = Series.new(categories)
  end

  if categories.empty?
    @categories = Series.new("category", [], dtype: String)
    return
  end

  if categories.null_count > 0
    msg = "Enum categories must not contain null values"
    raise TypeError, msg
  end

  if (dtype = categories.dtype) != String
    msg = "Enum categories must be strings; found data of type #{dtype}"
    raise TypeError, msg
  end

  if categories.n_unique != categories.len
    duplicate = categories.filter(categories.is_duplicated)[0]
    msg = "Enum categories must be unique; found duplicate #{duplicate}"
    raise ArgumentError, msg
  end

  @categories = categories.rechunk.alias("category")
end

Instance Attribute Details

#categories ⇒ Object (readonly)

Returns the value of attribute categories.



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# File 'lib/polars/data_types.rb', line 366

def categories
  @categories
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/polars/data_types.rb', line 397

def ==(other)
  if other.eql?(Enum)
    true
  elsif other.is_a?(Enum)
    categories == other.categories
  else
    false
  end
end

#to_s ⇒ Object 



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# File 'lib/polars/data_types.rb', line 407

def to_s
  "#{self.class.name}(categories: #{categories.to_a.inspect})"
end