Class: Arrow::Table

Inherits:
Object
  • Object
show all
Includes:
ColumnContainable, GenericFilterable, GenericTakeable, RecordContainable
Defined in:
lib/arrow/table.rb

Class Method Summary collapse

Instance Method Summary collapse

Methods included from RecordContainable

#each_record

Methods included from GenericTakeable

included, #take_generic

Methods included from GenericFilterable

#filter_generic, included

Methods included from ColumnContainable

#columns, #each_column, #find_column

Constructor Details

#initialize(columns) ⇒ Table #initialize(raw_table) ⇒ Table #initialize(raw_table) ⇒ Table #initialize(raw_table) ⇒ Table #initialize(schema, columns) ⇒ Table #initialize(schema, arrays) ⇒ Table #initialize(schema, record_batches) ⇒ Table #initialize(schema, raw_records) ⇒ Table

Creates a new Arrow::Table.

Overloads:

  • #initialize(columns) ⇒ Table

    Examples:

    Create a table from columns

    count_field = Arrow::Field.new("count", :uint32)
count_array = Arrow::UInt32Array.new([0, 2, nil, 4])
count_column = Arrow::Column.new(count_field, count_array)
visible_field = Arrow::Field.new("visible", :boolean)
visible_array = Arrow::BooleanArray.new([true, nil, nil, false])
visible_column = Arrow::Column.new(visible_field, visible_array)
Arrow::Table.new([count_column, visible_column])

    Parameters:

  • #initialize(raw_table) ⇒ Table

    Examples:

    Create a table from column name and values

    Arrow::Table.new("count" => Arrow::UInt32Array.new([0, 2, nil, 4]),
                 "visible" => Arrow::BooleanArray.new([true, nil, nil, false]))

    Parameters:

    • raw_table (Hash<String, Arrow::Array>) —

      The pairs of column name and values of the table. Column values is ‘Arrow::Array`.

  • #initialize(raw_table) ⇒ Table

    Examples:

    Create a table from column name and values

    count_chunks = [
  Arrow::UInt32Array.new([0, 2]),
  Arrow::UInt32Array.new([nil, 4]),
]
visible_chunks = [
  Arrow::BooleanArray.new([true]),
  Arrow::BooleanArray.new([nil, nil, false]),
]
Arrow::Table.new("count" => Arrow::ChunkedArray.new(count_chunks),
                 "visible" => Arrow::ChunkedArray.new(visible_chunks))

    Parameters:

    • raw_table (Hash<String, Arrow::ChunkedArray>) —

      The pairs of column name and values of the table. Column values is ‘Arrow::ChunkedArray`.

  • #initialize(raw_table) ⇒ Table

    Examples:

    Create a table from column name and values

    Arrow::Table.new("count" => [0, 2, nil, 4],
                 "visible" => [true, nil, nil, false])

    Parameters:

    • raw_table (Hash<String, ::Array>) —

      The pairs of column name and values of the table. Column values is ‘Array`.

  • #initialize(schema, columns) ⇒ Table

    Examples:

    Create a table from schema and columns

    count_field = Arrow::Field.new("count", :uint32)
count_array = Arrow::UInt32Array.new([0, 2, nil, 4])
count_column = Arrow::Column.new(count_field, count_array)
visible_field = Arrow::Field.new("visible", :boolean)
visible_array = Arrow::BooleanArray.new([true, nil, nil, false])
visible_column = Arrow::Column.new(visible_field, visible_array)
Arrow::Table.new(Arrow::Schema.new([count_field, visible_field]),
                 [count_column, visible_column])

    Parameters:

  • #initialize(schema, arrays) ⇒ Table

    Examples:

    Create a table from schema and arrays

    count_field = Arrow::Field.new("count", :uint32)
count_array = Arrow::UInt32Array.new([0, 2, nil, 4])
visible_field = Arrow::Field.new("visible", :boolean)
visible_array = Arrow::BooleanArray.new([true, nil, nil, false])
Arrow::Table.new(Arrow::Schema.new([count_field, visible_field]),
                 [count_array, visible_array])

    Parameters:

  • #initialize(schema, record_batches) ⇒ Table

    Examples:

    Create a table from schema and record batches

    count_field = Arrow::Field.new("count", :uint32)
visible_field = Arrow::Field.new("visible", :boolean)
schema = Arrow::Schema.new([count_field, visible_field])
record_batches = [
  Arrow::RecordBatch.new(schema, [[0, true], [2, nil], [nil, nil]]),
  Arrow::RecordBatch.new(schema, [[4, false]]),
]
Arrow::Table.new(schema, record_batches)

    Parameters:

  • #initialize(schema, raw_records) ⇒ Table

    Examples:

    Create a table from schema and raw records

    schema = {
  count: :uint32,
  visible: :boolean,
}
raw_records = [
  [0, true],
  [2, nil],
  [nil, nil],
  [4, false],
]
Arrow::Table.new(schema, raw_records)

    Parameters:

    • schema (Arrow::Schema) —

      The schema of the table. You can also specify schema as primitive Ruby objects. See Schema#initialize for details.

    • arrays (::Array<::Array>) —

      The data of the table as primitive Ruby objects.



162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
 
# File 'lib/arrow/table.rb', line 162

def initialize(*args)
  n_args = args.size
  case n_args
  when 1
    raw_table_converter = RawTableConverter.new(args[0])
    schema = raw_table_converter.schema
    values = raw_table_converter.values
  when 2
    schema = args[0]
    schema = Schema.new(schema) unless schema.is_a?(Schema)
    values = args[1]
    case values[0]
    when ::Array
      values = [RecordBatch.new(schema, values)]
    when Column
      values = values.collect(&:data)
    end
  else
    message = "wrong number of arguments (given #{n_args}, expected 1..2)"
    raise ArgumentError, message
  end
  initialize_raw(schema, values)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args, &block) ⇒ Object 



485
486
487
488
489
490
491
 
# File 'lib/arrow/table.rb', line 485

def method_missing(name, *args, &block)
  if args.empty?
    column = find_column(name)
    return column if column
  end
  super
end

Class Method Details

.load(path, options = {}) ⇒ Object 



28
29
30
 
# File 'lib/arrow/table.rb', line 28

def load(path, options={})
  TableLoader.load(path, options)
end

Instance Method Details

#each_record_batch ⇒ Object 



186
187
188
189
190
191
192
193
 
# File 'lib/arrow/table.rb', line 186

def each_record_batch
  return to_enum(__method__) unless block_given?

  reader = TableBatchReader.new(self)
  while record_batch = reader.read_next
    yield(record_batch)
  end
end

#group(*keys) ⇒ Object

Experimental



436
437
438
 
# File 'lib/arrow/table.rb', line 436

def group(*keys)
  Group.new(self, keys)
end

#inspect ⇒ Object 



476
477
478
 
# File 'lib/arrow/table.rb', line 476

def inspect
  "#{super}\n#{to_s}"
end

#inspect_raw ⇒ Object 



475
 
# File 'lib/arrow/table.rb', line 475

alias_method :inspect_raw, :inspect

#merge(other) ⇒ Arrow::Table

TODO

Returns:



329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
 
# File 'lib/arrow/table.rb', line 329

def merge(other)
  added_columns = {}
  removed_columns = {}

  case other
  when Hash
    other.each do |name, value|
      name = name.to_s
      if value
        added_columns[name] = ensure_raw_column(name, value)
      else
        removed_columns[name] = true
      end
    end
  when Table
    added_columns = {}
    other.columns.each do |column|
      name = column.name
      added_columns[name] = ensure_raw_column(name, column)
    end
  else
    message = "merge target must be Hash or Arrow::Table: " +
      "<#{other.inspect}>: #{inspect}"
    raise ArgumentError, message
  end

  new_columns = []
  columns.each do |column|
    column_name = column.name
    new_column = added_columns.delete(column_name)
    if new_column
      new_columns << new_column
      next
    end
    next if removed_columns.key?(column_name)
    new_columns << ensure_raw_column(column_name, column)
  end
  added_columns.each do |name, new_column|
    new_columns << new_column
  end
  new_fields = []
  new_arrays = []
  new_columns.each do |new_column|
    new_fields << new_column[:field]
    new_arrays << new_column[:data]
  end
  self.class.new(new_fields, new_arrays)
end

#pack ⇒ Object 



450
451
452
453
454
455
 
# File 'lib/arrow/table.rb', line 450

def pack
  packed_arrays = columns.collect do |column|
    column.data.pack
  end
  self.class.new(schema, packed_arrays)
end

#remove_column(name_or_index) ⇒ Object 



379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
 
# File 'lib/arrow/table.rb', line 379

def remove_column(name_or_index)
  case name_or_index
  when String, Symbol
    name = name_or_index.to_s
    index = columns.index {|column| column.name == name}
    if index.nil?
      message = "unknown column: #{name_or_index.inspect}: #{inspect}"
      raise KeyError.new(message)
    end
  else
    index = name_or_index
    index += n_columns if index < 0
    if index < 0 or index >= n_columns
      message = "out of index (0..#{n_columns - 1}): " +
        "#{name_or_index.inspect}: #{inspect}"
      raise IndexError.new(message)
    end
  end
  remove_column_raw(index)
end

#remove_column_raw ⇒ Object 



378
 
# File 'lib/arrow/table.rb', line 378

alias_method :remove_column_raw, :remove_column

#respond_to_missing?(name, include_private) ⇒ Boolean

Returns:

  • (Boolean) 


480
481
482
483
 
# File 'lib/arrow/table.rb', line 480

def respond_to_missing?(name, include_private)
  return true if find_column(name)
  super
end

#save(path, options = {}) ⇒ Object 



445
446
447
448
 
# File 'lib/arrow/table.rb', line 445

def save(path, options={})
  saver = TableSaver.new(self, path, options)
  saver.save
end

#select_columns(*selectors, &block) ⇒ Arrow::Table

TODO

Returns:



403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
 
# File 'lib/arrow/table.rb', line 403

def select_columns(*selectors, &block)
  if selectors.empty?
    return to_enum(__method__) unless block_given?
    selected_columns = columns.select(&block)
  else
    selected_columns = []
    selectors.each do |selector|
      case selector
      when String, Symbol
        column = find_column(selector)
        if column.nil?
          message = "unknown column: #{selector.inspect}: #{inspect}"
          raise KeyError.new(message)
        end
        selected_columns << column
      when Range
        selected_columns.concat(columns[selector])
      else
        column = columns[selector]
        if column.nil?
          message = "out of index (0..#{n_columns - 1}): " +
          "#{selector.inspect}: #{inspect}"
          raise IndexError.new(message)
        end
        selected_columns << column
      end
    end
    selected_columns = selected_columns.select(&block) if block_given?
  end
  self.class.new(selected_columns)
end

#slice(offset, length) ⇒ Arrow::Table #slice(index) ⇒ Arrow::Record #slice(booleans) ⇒ Arrow::Table #slice(boolean_array) ⇒ Arrow::Table #slice(range) ⇒ Arrow::Table #slice {|slicer| ... } ⇒ Arrow::Table

Overloads:

  • #slice(offset, length) ⇒ Arrow::Table

    Returns The sub ‘Arrow::Table` that covers only from `offset` to `offset + length` range.

    Parameters:

    • offset (Integer) —

      The offset of sub Arrow::Table.

    • length (Integer) —

      The length of sub Arrow::Table.

    Returns:

    • (Arrow::Table) —

      The sub ‘Arrow::Table` that covers only from `offset` to `offset + length` range.

  • #slice(index) ⇒ Arrow::Record

    Returns The ‘Arrow::Record` corresponding to index of the table.

    Parameters:

    • index (Integer) —

      The index in this table.

    Returns:

    • (Arrow::Record) —

      The ‘Arrow::Record` corresponding to index of the table.

  • #slice(booleans) ⇒ Arrow::Table

    Returns The sub ‘Arrow::Table` that covers only rows of indices the values of `booleans` is true.

    Parameters:

    • booleans (::Array<Boolean>) —

      The values indicating the target rows.

    Returns:

    • (Arrow::Table) —

      The sub ‘Arrow::Table` that covers only rows of indices the values of `booleans` is true.

  • #slice(boolean_array) ⇒ Arrow::Table

    Returns The sub ‘Arrow::Table` that covers only rows of indices the values of `boolean_array` is true.

    Parameters:

    • boolean_array (::Array<Arrow::BooleanArray>) —

      The values indicating the target rows.

    Returns:

    • (Arrow::Table) —

      The sub ‘Arrow::Table` that covers only rows of indices the values of `boolean_array` is true.

  • #slice(range) ⇒ Arrow::Table

    Returns The sub ‘Arrow::Table` that covers only rows of the range of indices.

    Parameters:

    • range_included_end (Range) —

      The range indicating the target rows.

    Returns:

    • (Arrow::Table) —

      The sub ‘Arrow::Table` that covers only rows of the range of indices.

  • #slice {|slicer| ... } ⇒ Arrow::Table

    Returns The sub ‘Arrow::Table` that covers only rows matched by condition specified by slicer.

    Yields:

    • (slicer) —

      Gives slicer that constructs condition to select records.

    Yield Parameters:

    • slicer (Arrow::Slicer) —

      The slicer that helps us to build condition.

    Yield Returns:

    Returns:

    • (Arrow::Table) —

      The sub ‘Arrow::Table` that covers only rows matched by condition specified by slicer.



249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
 
# File 'lib/arrow/table.rb', line 249

def slice(*args)
  slicers = []
  if block_given?
    unless args.empty?
      raise ArgumentError, "must not specify both arguments and block"
    end
    block_slicer = yield(Slicer.new(self))
    case block_slicer
    when ::Array
      slicers.concat(block_slicer)
    else
      slicers << block_slicer
    end
  else
    expected_n_args = nil
    case args.size
    when 1
      if args[0].is_a?(Integer)
        index = args[0]
        index += n_rows if index < 0
        return nil if index < 0
        return nil if index >= n_rows
        return Record.new(self, index)
      else
        slicers << args[0]
      end
    when 2
      offset, length = args
      slicers << (offset...(offset + length))
    else
      expected_n_args = "1..2"
    end
    if expected_n_args
      message = "wrong number of arguments " +
        "(given #{args.size}, expected #{expected_n_args})"
      raise ArgumentError, message
    end
  end

  filter_options = Arrow::FilterOptions.new
  filter_options.null_selection_behavior = :emit_null
  sliced_tables = []
  slicers.each do |slicer|
    slicer = slicer.evaluate if slicer.respond_to?(:evaluate)
    case slicer
    when Integer
      slicer += n_rows if slicer < 0
      sliced_tables << slice_by_range(slicer, n_rows - 1)
    when Range
      original_from = from = slicer.first
      to = slicer.last
      to -= 1 if slicer.exclude_end?
      from += n_rows if from < 0
      if from < 0 or from >= n_rows
        message =
          "offset is out of range (-#{n_rows + 1},#{n_rows}): " +
          "#{original_from}"
        raise ArgumentError, message
      end
      to += n_rows if to < 0
      sliced_tables << slice_by_range(from, to)
    when ::Array, BooleanArray, ChunkedArray
      sliced_tables << filter(slicer, filter_options)
    else
      message = "slicer must be Integer, Range, (from, to), " +
        "Arrow::ChunkedArray of Arrow::BooleanArray, " +
        "Arrow::BooleanArray or Arrow::Slicer::Condition: #{slicer.inspect}"
      raise ArgumentError, message
    end
  end
  if sliced_tables.size > 1
    sliced_tables[0].concatenate(sliced_tables[1..-1])
  else
    sliced_tables[0]
  end
end

#slice_raw ⇒ Object 



200
 
# File 'lib/arrow/table.rb', line 200

alias_method :slice_raw, :slice

#to_s(options = {}) ⇒ Object 



458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
 
# File 'lib/arrow/table.rb', line 458

def to_s(options={})
  format = options[:format]
  case format
  when :column
    return to_s_raw
  when :list
    formatter_class = TableListFormatter
  when :table, nil
    formatter_class = TableTableFormatter
  else
    message = ":format must be :column, :list, :table or nil"
    raise ArgumentError, "#{message}: <#{format.inspect}>"
  end
  formatter = formatter_class.new(self, options)
  formatter.format
end

#to_s_raw ⇒ Object 



457
 
# File 'lib/arrow/table.rb', line 457

alias_method :to_s_raw, :to_s

#window(size: nil) ⇒ Object

Experimental



441
442
443
 
# File 'lib/arrow/table.rb', line 441

def window(size: nil)
  RollingWindow.new(self, size)
end