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.


Class Methods


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 CSV::Row.header_row?() and CSV::Row.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()

Instance Methods


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.

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

Looks up the field by the semantics described in CSV::Row.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.

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

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.

If no block is given, an Enumerator is returned.

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

If no block is given, an Enumerator is returned.

Support for Enumerable.

This method will fetch the field value by header. It has the same behavior as Hash#fetch: if there is a field with the given header, its value is returned. Otherwise, if a block is given, it is yielded the header and its result is returned; if a default is given as the second argument, it is returned; otherwise a KeyError is raised.

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

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

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

Returns true if this is a field row.

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 CSV::Row.field().

If called with no arguments, all fields are returned.

Returns true if there is a field with the given header.

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

Returns true if this is a header row.

Returns the headers of this row.

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 CSV::Row.field().

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

An alias for has_key?

A shortcut for appending multiple fields. Equivalent to:

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

This method returns the row for chaining.

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

csv_row.fields.to_csv( options )

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

An alias for to_csv