A CSV::Row is part Array and part Hash. It retains an order for the fields and allows duplicates just as an Array would, but also allows you to access fields by name just as you could if they were in a Hash.

All rows returned by CSV will be constructed from this class, if header row processing is activated.

Methods
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Included Modules
Attributes
[R] row

Internal data format used to compare equality.
Class Public methods
new(headers, fields, header_row = false)

Construct a new CSV::Row from headers and fields, which are expected to be Arrays. If one Array is shorter than the other, it will be padded with nil objects.

The optional header_row parameter can be set to true to indicate, via #header_row? and #field_row?, that this is a header row. Otherwise, the row is assumes to be a field row.

A CSV::Row object supports the following Array methods through delegation:

  • empty?()

  • length()

  • size()

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 235
def initialize(headers, fields, header_row = false)
  @header_row = header_row

  # handle extra headers or fields
  @row = if headers.size > fields.size
    headers.zip(fields)
  else
    fields.zip(headers).map { |pair| pair.reverse }
  end
end
Instance Public methods
<<( field ) <<( header_and_field_array ) <<( header_and_field_hash )

If a two-element Array is provided, it is assumed to be a header and field and the pair is appended. A Hash works the same way with the key being the header and the value being the field. Anything else is assumed to be a lone field which is appended with a nil header.

This method returns the row for chaining.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 339
def <<(arg)
  if arg.is_a?(Array) and arg.size == 2  # appending a header and name
    @row << arg
  elsif arg.is_a?(Hash)                  # append header and name pairs
    arg.each { |pair| @row << pair }
  else                                   # append field value
    @row << [nil, arg]
  end

  self  # for chaining
end
==(other)

Returns true if this row contains the same headers and fields in the same order as other.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 476
def ==(other)
  @row == other.row
end
[](header_or_index, minimum_index = 0)
Alias for: field
[]=( header, value ) []=( header, offset, value ) []=( index, value )

Looks up the field by the semantics described in #field and assigns the value.

Assigning past the end of the row with an index will set all pairs between to [nil, nil]. Assigning to an unused header appends the new pair.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 306
def []=(*args)
  value = args.pop

  if args.first.is_a? Integer
    if @row[args.first].nil?  # extending past the end with index
      @row[args.first] = [nil, value]
      @row.map! { |pair| pair.nil? ? [nil, nil] : pair }
    else                      # normal index assignment
      @row[args.first][1] = value
    end
  else
    index = index(*args)
    if index.nil?             # appending a field
      self << [args.first, value]
    else                      # normal header assignment
      @row[index][1] = value
    end
  end
end
delete( header ) delete( header, offset ) delete( index )

Used to remove a pair from the row by header or index. The pair is located as described in #field. The deleted pair is returned, or nil if a pair could not be found.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 374
def delete(header_or_index, minimum_index = 0)
  if header_or_index.is_a? Integer                 # by index
    @row.delete_at(header_or_index)
  elsif i = index(header_or_index, minimum_index)  # by header
    @row.delete_at(i)
  else
    [ ]
  end
end
delete_if(&block)

The provided block is passed a header and field for each pair in the row and expected to return true or false, depending on whether the pair should be deleted.

This method returns the row for chaining.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 391
def delete_if(&block)
  @row.delete_if(&block)

  self  # for chaining
end
each(&block)

Yields each pair of the row as header and field tuples (much like iterating over a Hash).

Support for Enumerable.

This method returns the row for chaining.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 466
def each(&block)
  @row.each(&block)

  self  # for chaining
end
field( header ) field( header, offset ) field( index )

This method will fetch the field value by header or index. If a field is not found, nil is returned.

When provided, offset ensures that a header match occurrs on or later than the offset index. You can use this to find duplicate headers, without resorting to hard-coding exact indices.

Also aliased as: []

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 283
def field(header_or_index, minimum_index = 0)
  # locate the pair
  finder = header_or_index.is_a?(Integer) ? :[] : :assoc
  pair   = @row[minimum_index..-1].send(finder, header_or_index)

  # return the field if we have a pair
  pair.nil? ? nil : pair.last
end
field?(data)

Returns true if data matches a field in this row, and false otherwise.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 452
def field?(data)
  fields.include? data
end
field_row?()

Returns true if this is a field row.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 261
def field_row?
  not header_row?
end
fields(*headers_and_or_indices)

This method accepts any number of arguments which can be headers, indices, Ranges of either, or two-element Arrays containing a header and offset. Each argument will be replaced with a field lookup as described in #field.

If called with no arguments, all fields are returned.

Also aliased as: values_at

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 405
def fields(*headers_and_or_indices)
  if headers_and_or_indices.empty?  # return all fields--no arguments
    @row.map { |pair| pair.last }
  else                              # or work like values_at()
    headers_and_or_indices.inject(Array.new) do |all, h_or_i|
      all + if h_or_i.is_a? Range
        index_begin = h_or_i.begin.is_a?(Integer) ? h_or_i.begin :
                                                    index(h_or_i.begin)
        index_end   = h_or_i.end.is_a?(Integer)   ? h_or_i.end :
                                                    index(h_or_i.end)
        new_range   = h_or_i.exclude_end? ? (index_begin...index_end) :
                                            (index_begin..index_end)
        fields.values_at(new_range)
      else
        [field(*Array(h_or_i))]
      end
    end
  end
end
header?(name)

Returns true if name is a header for this row, and false otherwise.

Also aliased as: include?

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 443
def header?(name)
  headers.include? name
end
header_row?()

Returns true if this is a header row.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 256
def header_row?
  @header_row
end
headers()

Returns the headers of this row.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 266
def headers
  @row.map { |pair| pair.first }
end
include?(name)
Alias for: header?
index( header ) index( header, offset )

This method will return the index of a field with the provided header. The offset can be used to locate duplicate header names, as described in #field.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 435
def index(header, minimum_index = 0)
  # find the pair
  index = headers[minimum_index..-1].index(header)
  # return the index at the right offset, if we found one
  index.nil? ? nil : index + minimum_index
end
inspect()

A summary of fields, by header, in an ASCII compatible String.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 500
def inspect
  str = ["#<", self.class.to_s]
  each do |header, field|
    str << " " << (header.is_a?(Symbol) ? header.to_s : header.inspect) <<
           ":" << field.inspect
  end
  str << ">"
  begin
    str.join('')
  rescue  # any encoding error
    str.map do |s|
      e = Encoding::Converter.asciicompat_encoding(s.encoding)
      e ? s.encode(e) : s.force_encoding("ASCII-8BIT")
    end.join('')
  end
end
push(*args)

A shortcut for appending multiple fields. Equivalent to:

args.each { |arg| csv_row << arg }

This method returns the row for chaining.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 358
def push(*args)
  args.each { |arg| self << arg }

  self  # for chaining
end
to_csv(options = Hash.new)

Returns the row as a CSV String. Headers are not used. Equivalent to:

csv_row.fields.to_csv( options )
Also aliased as: to_s

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 494
def to_csv(options = Hash.new)
  fields.to_csv(options)
end
to_hash()

Collapses the row into a simple Hash. Be warning that this discards field order and clobbers duplicate fields.

Source: show | on GitHub 

# File ../ruby/lib/csv.rb, line 484
def to_hash
  # flatten just one level of the internal Array
  Hash[*@row.inject(Array.new) { |ary, pair| ary.push(*pair) }]
end
to_s(options = Hash.new)
Alias for: to_csv
values_at(*headers_and_or_indices)
Alias for: fields