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ruby--ruby/lib/csv.rb
Kazuhiro NISHIYAMA d8e90f5558
Fix a typo in inspect
2019-07-25 16:39:28 +09:00

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# encoding: US-ASCII
# frozen_string_literal: true
# = csv.rb -- CSV Reading and Writing
#
# Created by James Edward Gray II on 2005-10-31.
#
# See CSV for documentation.
#
# == Description
#
# Welcome to the new and improved CSV.
#
# This version of the CSV library began its life as FasterCSV. FasterCSV was
# intended as a replacement to Ruby's then standard CSV library. It was
# designed to address concerns users of that library had and it had three
# primary goals:
#
# 1. Be significantly faster than CSV while remaining a pure Ruby library.
# 2. Use a smaller and easier to maintain code base. (FasterCSV eventually
# grew larger, was also but considerably richer in features. The parsing
# core remains quite small.)
# 3. Improve on the CSV interface.
#
# Obviously, the last one is subjective. I did try to defer to the original
# interface whenever I didn't have a compelling reason to change it though, so
# hopefully this won't be too radically different.
#
# We must have met our goals because FasterCSV was renamed to CSV and replaced
# the original library as of Ruby 1.9. If you are migrating code from 1.8 or
# earlier, you may have to change your code to comply with the new interface.
#
# == What's Different From the Old CSV?
#
# I'm sure I'll miss something, but I'll try to mention most of the major
# differences I am aware of, to help others quickly get up to speed:
#
# === CSV Parsing
#
# * This parser is m17n aware. See CSV for full details.
# * This library has a stricter parser and will throw MalformedCSVErrors on
# problematic data.
# * This library has a less liberal idea of a line ending than CSV. What you
# set as the <tt>:row_sep</tt> is law. It can auto-detect your line endings
# though.
# * The old library returned empty lines as <tt>[nil]</tt>. This library calls
# them <tt>[]</tt>.
# * This library has a much faster parser.
#
# === Interface
#
# * CSV now uses Hash-style parameters to set options.
# * CSV no longer has generate_row() or parse_row().
# * The old CSV's Reader and Writer classes have been dropped.
# * CSV::open() is now more like Ruby's open().
# * CSV objects now support most standard IO methods.
# * CSV now has a new() method used to wrap objects like String and IO for
# reading and writing.
# * CSV::generate() is different from the old method.
# * CSV no longer supports partial reads. It works line-by-line.
# * CSV no longer allows the instance methods to override the separators for
# performance reasons. They must be set in the constructor.
#
# If you use this library and find yourself missing any functionality I have
# trimmed, please {let me know}[mailto:james@grayproductions.net].
#
# == Documentation
#
# See CSV for documentation.
#
# == What is CSV, really?
#
# CSV maintains a pretty strict definition of CSV taken directly from
# {the RFC}[http://www.ietf.org/rfc/rfc4180.txt]. I relax the rules in only one
# place and that is to make using this library easier. CSV will parse all valid
# CSV.
#
# What you don't want to do is feed CSV invalid data. Because of the way the
# CSV format works, it's common for a parser to need to read until the end of
# the file to be sure a field is invalid. This eats a lot of time and memory.
#
# Luckily, when working with invalid CSV, Ruby's built-in methods will almost
# always be superior in every way. For example, parsing non-quoted fields is as
# easy as:
#
# data.split(",")
#
# == Questions and/or Comments
#
# Feel free to email {James Edward Gray II}[mailto:james@grayproductions.net]
# with any questions.
require "forwardable"
require "English"
require "date"
require "stringio"
require_relative "csv/fields_converter"
require_relative "csv/match_p"
require_relative "csv/parser"
require_relative "csv/row"
require_relative "csv/table"
require_relative "csv/writer"
using CSV::MatchP if CSV.const_defined?(:MatchP)
#
# This class provides a complete interface to CSV files and data. It offers
# tools to enable you to read and write to and from Strings or IO objects, as
# needed.
#
# The most generic interface of the library is:
#
# csv = CSV.new(string_or_io, **options)
#
# # Reading: IO object should be open for read
# csv.read # => array of rows
# # or
# csv.each do |row|
# # ...
# end
# # or
# row = csv.shift
#
# # Writing: IO object should be open for write
# csv << row
#
# There are several specialized class methods for one-statement reading or writing,
# described in the Specialized Methods section.
#
# If a String is passed into ::new, it is internally wrapped into a StringIO object.
#
# +options+ can be used for specifying the particular CSV flavor (column
# separators, row separators, value quoting and so on), and for data conversion,
# see Data Conversion section for the description of the latter.
#
# == Specialized Methods
#
# === Reading
#
# # From a file: all at once
# arr_of_rows = CSV.read("path/to/file.csv", **options)
# # iterator-style:
# CSV.foreach("path/to/file.csv", **options) do |row|
# # ...
# end
#
# # From a string
# arr_of_rows = CSV.parse("CSV,data,String", **options)
# # or
# CSV.parse("CSV,data,String", **options) do |row|
# # ...
# end
#
# === Writing
#
# # To a file
# CSV.open("path/to/file.csv", "wb") do |csv|
# csv << ["row", "of", "CSV", "data"]
# csv << ["another", "row"]
# # ...
# end
#
# # To a String
# csv_string = CSV.generate do |csv|
# csv << ["row", "of", "CSV", "data"]
# csv << ["another", "row"]
# # ...
# end
#
# === Shortcuts
#
# # Core extensions for converting one line
# csv_string = ["CSV", "data"].to_csv # to CSV
# csv_array = "CSV,String".parse_csv # from CSV
#
# # CSV() method
# CSV { |csv_out| csv_out << %w{my data here} } # to $stdout
# CSV(csv = "") { |csv_str| csv_str << %w{my data here} } # to a String
# CSV($stderr) { |csv_err| csv_err << %w{my data here} } # to $stderr
# CSV($stdin) { |csv_in| csv_in.each { |row| p row } } # from $stdin
#
# == Data Conversion
#
# === CSV with headers
#
# CSV allows to specify column names of CSV file, whether they are in data, or
# provided separately. If headers specified, reading methods return an instance
# of CSV::Table, consisting of CSV::Row.
#
# # Headers are part of data
# data = CSV.parse(<<~ROWS, headers: true)
# Name,Department,Salary
# Bob,Engineering,1000
# Jane,Sales,2000
# John,Management,5000
# ROWS
#
# data.class #=> CSV::Table
# data.first #=> #<CSV::Row "Name":"Bob" "Department":"Engineering" "Salary":"1000">
# data.first.to_h #=> {"Name"=>"Bob", "Department"=>"Engineering", "Salary"=>"1000"}
#
# # Headers provided by developer
# data = CSV.parse('Bob,Engeneering,1000', headers: %i[name department salary])
# data.first #=> #<CSV::Row name:"Bob" department:"Engineering" salary:"1000">
#
# === Typed data reading
#
# CSV allows to provide a set of data _converters_ e.g. transformations to try on input
# data. Converter could be a symbol from CSV::Converters constant's keys, or lambda.
#
# # Without any converters:
# CSV.parse('Bob,2018-03-01,100')
# #=> [["Bob", "2018-03-01", "100"]]
#
# # With built-in converters:
# CSV.parse('Bob,2018-03-01,100', converters: %i[numeric date])
# #=> [["Bob", #<Date: 2018-03-01>, 100]]
#
# # With custom converters:
# CSV.parse('Bob,2018-03-01,100', converters: [->(v) { Time.parse(v) rescue v }])
# #=> [["Bob", 2018-03-01 00:00:00 +0200, "100"]]
#
# == CSV and Character Encodings (M17n or Multilingualization)
#
# This new CSV parser is m17n savvy. The parser works in the Encoding of the IO
# or String object being read from or written to. Your data is never transcoded
# (unless you ask Ruby to transcode it for you) and will literally be parsed in
# the Encoding it is in. Thus CSV will return Arrays or Rows of Strings in the
# Encoding of your data. This is accomplished by transcoding the parser itself
# into your Encoding.
#
# Some transcoding must take place, of course, to accomplish this multiencoding
# support. For example, <tt>:col_sep</tt>, <tt>:row_sep</tt>, and
# <tt>:quote_char</tt> must be transcoded to match your data. Hopefully this
# makes the entire process feel transparent, since CSV's defaults should just
# magically work for your data. However, you can set these values manually in
# the target Encoding to avoid the translation.
#
# It's also important to note that while all of CSV's core parser is now
# Encoding agnostic, some features are not. For example, the built-in
# converters will try to transcode data to UTF-8 before making conversions.
# Again, you can provide custom converters that are aware of your Encodings to
# avoid this translation. It's just too hard for me to support native
# conversions in all of Ruby's Encodings.
#
# Anyway, the practical side of this is simple: make sure IO and String objects
# passed into CSV have the proper Encoding set and everything should just work.
# CSV methods that allow you to open IO objects (CSV::foreach(), CSV::open(),
# CSV::read(), and CSV::readlines()) do allow you to specify the Encoding.
#
# One minor exception comes when generating CSV into a String with an Encoding
# that is not ASCII compatible. There's no existing data for CSV to use to
# prepare itself and thus you will probably need to manually specify the desired
# Encoding for most of those cases. It will try to guess using the fields in a
# row of output though, when using CSV::generate_line() or Array#to_csv().
#
# I try to point out any other Encoding issues in the documentation of methods
# as they come up.
#
# This has been tested to the best of my ability with all non-"dummy" Encodings
# Ruby ships with. However, it is brave new code and may have some bugs.
# Please feel free to {report}[mailto:james@grayproductions.net] any issues you
# find with it.
#
class CSV
# The error thrown when the parser encounters illegal CSV formatting.
class MalformedCSVError < RuntimeError
attr_reader :line_number
alias_method :lineno, :line_number
def initialize(message, line_number)
@line_number = line_number
super("#{message} in line #{line_number}.")
end
end
#
# A FieldInfo Struct contains details about a field's position in the data
# source it was read from. CSV will pass this Struct to some blocks that make
# decisions based on field structure. See CSV.convert_fields() for an
# example.
#
# <b><tt>index</tt></b>:: The zero-based index of the field in its row.
# <b><tt>line</tt></b>:: The line of the data source this row is from.
# <b><tt>header</tt></b>:: The header for the column, when available.
#
FieldInfo = Struct.new(:index, :line, :header)
# A Regexp used to find and convert some common Date formats.
DateMatcher = / \A(?: (\w+,?\s+)?\w+\s+\d{1,2},?\s+\d{2,4} |
\d{4}-\d{2}-\d{2} )\z /x
# A Regexp used to find and convert some common DateTime formats.
DateTimeMatcher =
/ \A(?: (\w+,?\s+)?\w+\s+\d{1,2}\s+\d{1,2}:\d{1,2}:\d{1,2},?\s+\d{2,4} |
\d{4}-\d{2}-\d{2}\s\d{2}:\d{2}:\d{2} |
# ISO-8601
\d{4}-\d{2}-\d{2}
(?:T\d{2}:\d{2}(?::\d{2}(?:\.\d+)?(?:[+-]\d{2}(?::\d{2})|Z)?)?)?
)\z /x
# The encoding used by all converters.
ConverterEncoding = Encoding.find("UTF-8")
#
# This Hash holds the built-in converters of CSV that can be accessed by name.
# You can select Converters with CSV.convert() or through the +options+ Hash
# passed to CSV::new().
#
# <b><tt>:integer</tt></b>:: Converts any field Integer() accepts.
# <b><tt>:float</tt></b>:: Converts any field Float() accepts.
# <b><tt>:numeric</tt></b>:: A combination of <tt>:integer</tt>
# and <tt>:float</tt>.
# <b><tt>:date</tt></b>:: Converts any field Date::parse() accepts.
# <b><tt>:date_time</tt></b>:: Converts any field DateTime::parse() accepts.
# <b><tt>:all</tt></b>:: All built-in converters. A combination of
# <tt>:date_time</tt> and <tt>:numeric</tt>.
#
# All built-in converters transcode field data to UTF-8 before attempting a
# conversion. If your data cannot be transcoded to UTF-8 the conversion will
# fail and the field will remain unchanged.
#
# This Hash is intentionally left unfrozen and users should feel free to add
# values to it that can be accessed by all CSV objects.
#
# To add a combo field, the value should be an Array of names. Combo fields
# can be nested with other combo fields.
#
Converters = {
integer: lambda { |f|
Integer(f.encode(ConverterEncoding)) rescue f
},
float: lambda { |f|
Float(f.encode(ConverterEncoding)) rescue f
},
numeric: [:integer, :float],
date: lambda { |f|
begin
e = f.encode(ConverterEncoding)
e.match?(DateMatcher) ? Date.parse(e) : f
rescue # encoding conversion or date parse errors
f
end
},
date_time: lambda { |f|
begin
e = f.encode(ConverterEncoding)
e.match?(DateTimeMatcher) ? DateTime.parse(e) : f
rescue # encoding conversion or date parse errors
f
end
},
all: [:date_time, :numeric],
}
#
# This Hash holds the built-in header converters of CSV that can be accessed
# by name. You can select HeaderConverters with CSV.header_convert() or
# through the +options+ Hash passed to CSV::new().
#
# <b><tt>:downcase</tt></b>:: Calls downcase() on the header String.
# <b><tt>:symbol</tt></b>:: Leading/trailing spaces are dropped, string is
# downcased, remaining spaces are replaced with
# underscores, non-word characters are dropped,
# and finally to_sym() is called.
#
# All built-in header converters transcode header data to UTF-8 before
# attempting a conversion. If your data cannot be transcoded to UTF-8 the
# conversion will fail and the header will remain unchanged.
#
# This Hash is intentionally left unfrozen and users should feel free to add
# values to it that can be accessed by all CSV objects.
#
# To add a combo field, the value should be an Array of names. Combo fields
# can be nested with other combo fields.
#
HeaderConverters = {
downcase: lambda { |h| h.encode(ConverterEncoding).downcase },
symbol: lambda { |h|
h.encode(ConverterEncoding).downcase.gsub(/[^\s\w]+/, "").strip.
gsub(/\s+/, "_").to_sym
}
}
#
# The options used when no overrides are given by calling code. They are:
#
# <b><tt>:col_sep</tt></b>:: <tt>","</tt>
# <b><tt>:row_sep</tt></b>:: <tt>:auto</tt>
# <b><tt>:quote_char</tt></b>:: <tt>'"'</tt>
# <b><tt>:field_size_limit</tt></b>:: +nil+
# <b><tt>:converters</tt></b>:: +nil+
# <b><tt>:unconverted_fields</tt></b>:: +nil+
# <b><tt>:headers</tt></b>:: +false+
# <b><tt>:return_headers</tt></b>:: +false+
# <b><tt>:header_converters</tt></b>:: +nil+
# <b><tt>:skip_blanks</tt></b>:: +false+
# <b><tt>:force_quotes</tt></b>:: +false+
# <b><tt>:skip_lines</tt></b>:: +nil+
# <b><tt>:liberal_parsing</tt></b>:: +false+
# <b><tt>:quote_empty</tt></b>:: +true+
#
DEFAULT_OPTIONS = {
col_sep: ",",
row_sep: :auto,
quote_char: '"',
field_size_limit: nil,
converters: nil,
unconverted_fields: nil,
headers: false,
return_headers: false,
header_converters: nil,
skip_blanks: false,
force_quotes: false,
skip_lines: nil,
liberal_parsing: false,
quote_empty: true,
}.freeze
#
# This method will return a CSV instance, just like CSV::new(), but the
# instance will be cached and returned for all future calls to this method for
# the same +data+ object (tested by Object#object_id()) with the same
# +options+.
#
# If a block is given, the instance is passed to the block and the return
# value becomes the return value of the block.
#
def self.instance(data = $stdout, **options)
# create a _signature_ for this method call, data object and options
sig = [data.object_id] +
options.values_at(*DEFAULT_OPTIONS.keys.sort_by { |sym| sym.to_s })
# fetch or create the instance for this signature
@@instances ||= Hash.new
instance = (@@instances[sig] ||= new(data, options))
if block_given?
yield instance # run block, if given, returning result
else
instance # or return the instance
end
end
#
# :call-seq:
# filter( **options ) { |row| ... }
# filter( input, **options ) { |row| ... }
# filter( input, output, **options ) { |row| ... }
#
# This method is a convenience for building Unix-like filters for CSV data.
# Each row is yielded to the provided block which can alter it as needed.
# After the block returns, the row is appended to +output+ altered or not.
#
# The +input+ and +output+ arguments can be anything CSV::new() accepts
# (generally String or IO objects). If not given, they default to
# <tt>ARGF</tt> and <tt>$stdout</tt>.
#
# The +options+ parameter is also filtered down to CSV::new() after some
# clever key parsing. Any key beginning with <tt>:in_</tt> or
# <tt>:input_</tt> will have that leading identifier stripped and will only
# be used in the +options+ Hash for the +input+ object. Keys starting with
# <tt>:out_</tt> or <tt>:output_</tt> affect only +output+. All other keys
# are assigned to both objects.
#
# The <tt>:output_row_sep</tt> +option+ defaults to
# <tt>$INPUT_RECORD_SEPARATOR</tt> (<tt>$/</tt>).
#
def self.filter(input=nil, output=nil, **options)
# parse options for input, output, or both
in_options, out_options = Hash.new, {row_sep: $INPUT_RECORD_SEPARATOR}
options.each do |key, value|
case key.to_s
when /\Ain(?:put)?_(.+)\Z/
in_options[$1.to_sym] = value
when /\Aout(?:put)?_(.+)\Z/
out_options[$1.to_sym] = value
else
in_options[key] = value
out_options[key] = value
end
end
# build input and output wrappers
input = new(input || ARGF, in_options)
output = new(output || $stdout, out_options)
# read, yield, write
input.each do |row|
yield row
output << row
end
end
#
# This method is intended as the primary interface for reading CSV files. You
# pass a +path+ and any +options+ you wish to set for the read. Each row of
# file will be passed to the provided +block+ in turn.
#
# The +options+ parameter can be anything CSV::new() understands. This method
# also understands an additional <tt>:encoding</tt> parameter that you can use
# to specify the Encoding of the data in the file to be read. You must provide
# this unless your data is in Encoding::default_external(). CSV will use this
# to determine how to parse the data. You may provide a second Encoding to
# have the data transcoded as it is read. For example,
# <tt>encoding: "UTF-32BE:UTF-8"</tt> would read UTF-32BE data from the file
# but transcode it to UTF-8 before CSV parses it.
#
def self.foreach(path, mode="r", **options, &block)
return to_enum(__method__, path, mode, options) unless block_given?
open(path, mode, options) do |csv|
csv.each(&block)
end
end
#
# :call-seq:
# generate( str, **options ) { |csv| ... }
# generate( **options ) { |csv| ... }
#
# This method wraps a String you provide, or an empty default String, in a
# CSV object which is passed to the provided block. You can use the block to
# append CSV rows to the String and when the block exits, the final String
# will be returned.
#
# Note that a passed String *is* modified by this method. Call dup() before
# passing if you need a new String.
#
# The +options+ parameter can be anything CSV::new() understands. This method
# understands an additional <tt>:encoding</tt> parameter when not passed a
# String to set the base Encoding for the output. CSV needs this hint if you
# plan to output non-ASCII compatible data.
#
def self.generate(str=nil, **options)
# add a default empty String, if none was given
if str
str = StringIO.new(str)
str.seek(0, IO::SEEK_END)
else
encoding = options[:encoding]
str = +""
str.force_encoding(encoding) if encoding
end
csv = new(str, options) # wrap
yield csv # yield for appending
csv.string # return final String
end
#
# This method is a shortcut for converting a single row (Array) into a CSV
# String.
#
# The +options+ parameter can be anything CSV::new() understands. This method
# understands an additional <tt>:encoding</tt> parameter to set the base
# Encoding for the output. This method will try to guess your Encoding from
# the first non-+nil+ field in +row+, if possible, but you may need to use
# this parameter as a backup plan.
#
# The <tt>:row_sep</tt> +option+ defaults to <tt>$INPUT_RECORD_SEPARATOR</tt>
# (<tt>$/</tt>) when calling this method.
#
def self.generate_line(row, **options)
options = {row_sep: $INPUT_RECORD_SEPARATOR}.merge(options)
str = +""
if options[:encoding]
str.force_encoding(options[:encoding])
elsif field = row.find {|f| f.is_a?(String)}
str.force_encoding(field.encoding)
end
(new(str, options) << row).string
end
#
# :call-seq:
# open( filename, mode = "rb", **options ) { |faster_csv| ... }
# open( filename, **options ) { |faster_csv| ... }
# open( filename, mode = "rb", **options )
# open( filename, **options )
#
# This method opens an IO object, and wraps that with CSV. This is intended
# as the primary interface for writing a CSV file.
#
# You must pass a +filename+ and may optionally add a +mode+ for Ruby's
# open(). You may also pass an optional Hash containing any +options+
# CSV::new() understands as the final argument.
#
# This method works like Ruby's open() call, in that it will pass a CSV object
# to a provided block and close it when the block terminates, or it will
# return the CSV object when no block is provided. (*Note*: This is different
# from the Ruby 1.8 CSV library which passed rows to the block. Use
# CSV::foreach() for that behavior.)
#
# You must provide a +mode+ with an embedded Encoding designator unless your
# data is in Encoding::default_external(). CSV will check the Encoding of the
# underlying IO object (set by the +mode+ you pass) to determine how to parse
# the data. You may provide a second Encoding to have the data transcoded as
# it is read just as you can with a normal call to IO::open(). For example,
# <tt>"rb:UTF-32BE:UTF-8"</tt> would read UTF-32BE data from the file but
# transcode it to UTF-8 before CSV parses it.
#
# An opened CSV object will delegate to many IO methods for convenience. You
# may call:
#
# * binmode()
# * binmode?()
# * close()
# * close_read()
# * close_write()
# * closed?()
# * eof()
# * eof?()
# * external_encoding()
# * fcntl()
# * fileno()
# * flock()
# * flush()
# * fsync()
# * internal_encoding()
# * ioctl()
# * isatty()
# * path()
# * pid()
# * pos()
# * pos=()
# * reopen()
# * seek()
# * stat()
# * sync()
# * sync=()
# * tell()
# * to_i()
# * to_io()
# * truncate()
# * tty?()
#
def self.open(filename, mode="r", **options)
# wrap a File opened with the remaining +args+ with no newline
# decorator
file_opts = {universal_newline: false}.merge(options)
begin
f = File.open(filename, mode, file_opts)
rescue ArgumentError => e
raise unless /needs binmode/.match?(e.message) and mode == "r"
mode = "rb"
file_opts = {encoding: Encoding.default_external}.merge(file_opts)
retry
end
begin
csv = new(f, options)
rescue Exception
f.close
raise
end
# handle blocks like Ruby's open(), not like the CSV library
if block_given?
begin
yield csv
ensure
csv.close
end
else
csv
end
end
#
# :call-seq:
# parse( str, **options ) { |row| ... }
# parse( str, **options )
#
# This method can be used to easily parse CSV out of a String. You may either
# provide a +block+ which will be called with each row of the String in turn,
# or just use the returned Array of Arrays (when no +block+ is given).
#
# You pass your +str+ to read from, and an optional +options+ containing
# anything CSV::new() understands.
#
def self.parse(*args, &block)
csv = new(*args)
return csv.each(&block) if block_given?
# slurp contents, if no block is given
begin
csv.read
ensure
csv.close
end
end
#
# This method is a shortcut for converting a single line of a CSV String into
# an Array. Note that if +line+ contains multiple rows, anything beyond the
# first row is ignored.
#
# The +options+ parameter can be anything CSV::new() understands.
#
def self.parse_line(line, **options)
new(line, options).shift
end
#
# Use to slurp a CSV file into an Array of Arrays. Pass the +path+ to the
# file and any +options+ CSV::new() understands. This method also understands
# an additional <tt>:encoding</tt> parameter that you can use to specify the
# Encoding of the data in the file to be read. You must provide this unless
# your data is in Encoding::default_external(). CSV will use this to determine
# how to parse the data. You may provide a second Encoding to have the data
# transcoded as it is read. For example,
# <tt>encoding: "UTF-32BE:UTF-8"</tt> would read UTF-32BE data from the file
# but transcode it to UTF-8 before CSV parses it.
#
def self.read(path, *options)
open(path, *options) { |csv| csv.read }
end
# Alias for CSV::read().
def self.readlines(*args)
read(*args)
end
#
# A shortcut for:
#
# CSV.read( path, { headers: true,
# converters: :numeric,
# header_converters: :symbol }.merge(options) )
#
def self.table(path, **options)
read( path, { headers: true,
converters: :numeric,
header_converters: :symbol }.merge(options) )
end
#
# This constructor will wrap either a String or IO object passed in +data+ for
# reading and/or writing. In addition to the CSV instance methods, several IO
# methods are delegated. (See CSV::open() for a complete list.) If you pass
# a String for +data+, you can later retrieve it (after writing to it, for
# example) with CSV.string().
#
# Note that a wrapped String will be positioned at the beginning (for
# reading). If you want it at the end (for writing), use CSV::generate().
# If you want any other positioning, pass a preset StringIO object instead.
#
# You may set any reading and/or writing preferences in the +options+ Hash.
# Available options are:
#
# <b><tt>:col_sep</tt></b>:: The String placed between each field.
# This String will be transcoded into
# the data's Encoding before parsing.
# <b><tt>:row_sep</tt></b>:: The String appended to the end of each
# row. This can be set to the special
# <tt>:auto</tt> setting, which requests
# that CSV automatically discover this
# from the data. Auto-discovery reads
# ahead in the data looking for the next
# <tt>"\r\n"</tt>, <tt>"\n"</tt>, or
# <tt>"\r"</tt> sequence. A sequence
# will be selected even if it occurs in
# a quoted field, assuming that you
# would have the same line endings
# there. If none of those sequences is
# found, +data+ is <tt>ARGF</tt>,
# <tt>STDIN</tt>, <tt>STDOUT</tt>, or
# <tt>STDERR</tt>, or the stream is only
# available for output, the default
# <tt>$INPUT_RECORD_SEPARATOR</tt>
# (<tt>$/</tt>) is used. Obviously,
# discovery takes a little time. Set
# manually if speed is important. Also
# note that IO objects should be opened
# in binary mode on Windows if this
# feature will be used as the
# line-ending translation can cause
# problems with resetting the document
# position to where it was before the
# read ahead. This String will be
# transcoded into the data's Encoding
# before parsing.
# <b><tt>:quote_char</tt></b>:: The character used to quote fields.
# This has to be a single character
# String. This is useful for
# application that incorrectly use
# <tt>'</tt> as the quote character
# instead of the correct <tt>"</tt>.
# CSV will always consider a double
# sequence of this character to be an
# escaped quote. This String will be
# transcoded into the data's Encoding
# before parsing.
# <b><tt>:field_size_limit</tt></b>:: This is a maximum size CSV will read
# ahead looking for the closing quote
# for a field. (In truth, it reads to
# the first line ending beyond this
# size.) If a quote cannot be found
# within the limit CSV will raise a
# MalformedCSVError, assuming the data
# is faulty. You can use this limit to
# prevent what are effectively DoS
# attacks on the parser. However, this
# limit can cause a legitimate parse to
# fail and thus is set to +nil+, or off,
# by default.
# <b><tt>:converters</tt></b>:: An Array of names from the Converters
# Hash and/or lambdas that handle custom
# conversion. A single converter
# doesn't have to be in an Array. All
# built-in converters try to transcode
# fields to UTF-8 before converting.
# The conversion will fail if the data
# cannot be transcoded, leaving the
# field unchanged.
# <b><tt>:unconverted_fields</tt></b>:: If set to +true+, an
# unconverted_fields() method will be
# added to all returned rows (Array or
# CSV::Row) that will return the fields
# as they were before conversion. Note
# that <tt>:headers</tt> supplied by
# Array or String were not fields of the
# document and thus will have an empty
# Array attached.
# <b><tt>:headers</tt></b>:: If set to <tt>:first_row</tt> or
# +true+, the initial row of the CSV
# file will be treated as a row of
# headers. If set to an Array, the
# contents will be used as the headers.
# If set to a String, the String is run
# through a call of CSV::parse_line()
# with the same <tt>:col_sep</tt>,
# <tt>:row_sep</tt>, and
# <tt>:quote_char</tt> as this instance
# to produce an Array of headers. This
# setting causes CSV#shift() to return
# rows as CSV::Row objects instead of
# Arrays and CSV#read() to return
# CSV::Table objects instead of an Array
# of Arrays.
# <b><tt>:return_headers</tt></b>:: When +false+, header rows are silently
# swallowed. If set to +true+, header
# rows are returned in a CSV::Row object
# with identical headers and
# fields (save that the fields do not go
# through the converters).
# <b><tt>:write_headers</tt></b>:: When +true+ and <tt>:headers</tt> is
# set, a header row will be added to the
# output.
# <b><tt>:header_converters</tt></b>:: Identical in functionality to
# <tt>:converters</tt> save that the
# conversions are only made to header
# rows. All built-in converters try to
# transcode headers to UTF-8 before
# converting. The conversion will fail
# if the data cannot be transcoded,
# leaving the header unchanged.
# <b><tt>:skip_blanks</tt></b>:: When set to a +true+ value, CSV will
# skip over any empty rows. Note that
# this setting will not skip rows that
# contain column separators, even if
# the rows contain no actual data. If
# you want to skip rows that contain
# separators but no content, consider
# using <tt>:skip_lines</tt>, or
# inspecting fields.compact.empty? on
# each row.
# <b><tt>:force_quotes</tt></b>:: When set to a +true+ value, CSV will
# quote all CSV fields it creates.
# <b><tt>:skip_lines</tt></b>:: When set to an object responding to
# <tt>match</tt>, every line matching
# it is considered a comment and ignored
# during parsing. When set to a String,
# it is first converted to a Regexp.
# When set to +nil+ no line is considered
# a comment. If the passed object does
# not respond to <tt>match</tt>,
# <tt>ArgumentError</tt> is thrown.
# <b><tt>:liberal_parsing</tt></b>:: When set to a +true+ value, CSV will
# attempt to parse input not conformant
# with RFC 4180, such as double quotes
# in unquoted fields.
# <b><tt>:nil_value</tt></b>:: When set an object, any values of an
# empty field are replaced by the set
# object, not nil.
# <b><tt>:empty_value</tt></b>:: When set an object, any values of a
# blank string field is replaced by
# the set object.
# <b><tt>:quote_empty</tt></b>:: When set to a +true+ value, CSV will
# quote empty values with double quotes.
# When +false+, CSV will emit an
# empty string for an empty field value.
# <b><tt>:write_converters</tt></b>:: Converts values on each line with the
# specified <tt>Proc</tt> object(s),
# which receive a <tt>String</tt> value
# and return a <tt>String</tt> or +nil+
# value.
# When an array is specified, each
# converter will be applied in order.
# <b><tt>:write_nil_value</tt></b>:: When a <tt>String</tt> value, +nil+
# value(s) on each line will be replaced
# with the specified value.
# <b><tt>:write_empty_value</tt></b>:: When a <tt>String</tt> or +nil+ value,
# empty value(s) on each line will be
# replaced with the specified value.
# <b><tt>:strip</tt></b>:: When set to a +true+ value, CSV will
# strip "\t\r\n\f\v" around the values.
# If you specify a string instead of
# +true+, CSV will strip string. The
# length of string must be 1.
#
# See CSV::DEFAULT_OPTIONS for the default settings.
#
# Options cannot be overridden in the instance methods for performance reasons,
# so be sure to set what you want here.
#
def initialize(data,
col_sep: ",",
row_sep: :auto,
quote_char: '"',
field_size_limit: nil,
converters: nil,
unconverted_fields: nil,
headers: false,
return_headers: false,
write_headers: nil,
header_converters: nil,
skip_blanks: false,
force_quotes: false,
skip_lines: nil,
liberal_parsing: false,
internal_encoding: nil,
external_encoding: nil,
encoding: nil,
nil_value: nil,
empty_value: "",
quote_empty: true,
write_converters: nil,
write_nil_value: nil,
write_empty_value: "",
strip: false)
raise ArgumentError.new("Cannot parse nil as CSV") if data.nil?
# create the IO object we will read from
@io = data.is_a?(String) ? StringIO.new(data) : data
@encoding = determine_encoding(encoding, internal_encoding)
@base_fields_converter_options = {
nil_value: nil_value,
empty_value: empty_value,
}
@write_fields_converter_options = {
nil_value: write_nil_value,
empty_value: write_empty_value,
}
@initial_converters = converters
@initial_header_converters = header_converters
@initial_write_converters = write_converters
@parser_options = {
column_separator: col_sep,
row_separator: row_sep,
quote_character: quote_char,
field_size_limit: field_size_limit,
unconverted_fields: unconverted_fields,
headers: headers,
return_headers: return_headers,
skip_blanks: skip_blanks,
skip_lines: skip_lines,
liberal_parsing: liberal_parsing,
encoding: @encoding,
nil_value: nil_value,
empty_value: empty_value,
strip: strip,
}
@parser = nil
@parser_enumerator = nil
@eof_error = nil
@writer_options = {
encoding: @encoding,
force_encoding: (not encoding.nil?),
force_quotes: force_quotes,
headers: headers,
write_headers: write_headers,
column_separator: col_sep,
row_separator: row_sep,
quote_character: quote_char,
quote_empty: quote_empty,
}
@writer = nil
writer if @writer_options[:write_headers]
end
#
# The encoded <tt>:col_sep</tt> used in parsing and writing. See CSV::new
# for details.
#
def col_sep
parser.column_separator
end
#
# The encoded <tt>:row_sep</tt> used in parsing and writing. See CSV::new
# for details.
#
def row_sep
parser.row_separator
end
#
# The encoded <tt>:quote_char</tt> used in parsing and writing. See CSV::new
# for details.
#
def quote_char
parser.quote_character
end
# The limit for field size, if any. See CSV::new for details.
def field_size_limit
parser.field_size_limit
end
# The regex marking a line as a comment. See CSV::new for details
def skip_lines
parser.skip_lines
end
#
# Returns the current list of converters in effect. See CSV::new for details.
# Built-in converters will be returned by name, while others will be returned
# as is.
#
def converters
parser_fields_converter.map do |converter|
name = Converters.rassoc(converter)
name ? name.first : converter
end
end
#
# Returns +true+ if unconverted_fields() to parsed results. See CSV::new
# for details.
#
def unconverted_fields?
parser.unconverted_fields?
end
#
# Returns +nil+ if headers will not be used, +true+ if they will but have not
# yet been read, or the actual headers after they have been read. See
# CSV::new for details.
#
def headers
if @writer
@writer.headers
else
parsed_headers = parser.headers
return parsed_headers if parsed_headers
raw_headers = @parser_options[:headers]
raw_headers = nil if raw_headers == false
raw_headers
end
end
#
# Returns +true+ if headers will be returned as a row of results.
# See CSV::new for details.
#
def return_headers?
parser.return_headers?
end
# Returns +true+ if headers are written in output. See CSV::new for details.
def write_headers?
@writer_options[:write_headers]
end
#
# Returns the current list of converters in effect for headers. See CSV::new
# for details. Built-in converters will be returned by name, while others
# will be returned as is.
#
def header_converters
header_fields_converter.map do |converter|
name = HeaderConverters.rassoc(converter)
name ? name.first : converter
end
end
#
# Returns +true+ blank lines are skipped by the parser. See CSV::new
# for details.
#
def skip_blanks?
parser.skip_blanks?
end
# Returns +true+ if all output fields are quoted. See CSV::new for details.
def force_quotes?
@writer_options[:force_quotes]
end
# Returns +true+ if illegal input is handled. See CSV::new for details.
def liberal_parsing?
parser.liberal_parsing?
end
#
# The Encoding CSV is parsing or writing in. This will be the Encoding you
# receive parsed data in and/or the Encoding data will be written in.
#
attr_reader :encoding
#
# The line number of the last row read from this file. Fields with nested
# line-end characters will not affect this count.
#
def lineno
if @writer
@writer.lineno
else
parser.lineno
end
end
#
# The last row read from this file.
#
def line
parser.line
end
### IO and StringIO Delegation ###
extend Forwardable
def_delegators :@io, :binmode, :close, :close_read, :close_write,
:closed?, :external_encoding, :fcntl,
:fileno, :flush, :fsync, :internal_encoding,
:isatty, :pid, :pos, :pos=, :reopen,
:seek, :string, :sync, :sync=, :tell,
:truncate, :tty?
def binmode?
if @io.respond_to?(:binmode?)
@io.binmode?
else
false
end
end
def flock(*args)
raise NotImplementedError unless @io.respond_to?(:flock)
@io.flock(*args)
end
def ioctl(*args)
raise NotImplementedError unless @io.respond_to?(:ioctl)
@io.ioctl(*args)
end
def path
@io.path if @io.respond_to?(:path)
end
def stat(*args)
raise NotImplementedError unless @io.respond_to?(:stat)
@io.stat(*args)
end
def to_i
raise NotImplementedError unless @io.respond_to?(:to_i)
@io.to_i
end
def to_io
@io.respond_to?(:to_io) ? @io.to_io : @io
end
def eof?
return false if @eof_error
begin
parser_enumerator.peek
false
rescue MalformedCSVError => error
@eof_error = error
false
rescue StopIteration
true
end
end
alias_method :eof, :eof?
# Rewinds the underlying IO object and resets CSV's lineno() counter.
def rewind
@parser = nil
@parser_enumerator = nil
@eof_error = nil
@writer.rewind if @writer
@io.rewind
end
### End Delegation ###
#
# The primary write method for wrapped Strings and IOs, +row+ (an Array or
# CSV::Row) is converted to CSV and appended to the data source. When a
# CSV::Row is passed, only the row's fields() are appended to the output.
#
# The data source must be open for writing.
#
def <<(row)
writer << row
self
end
alias_method :add_row, :<<
alias_method :puts, :<<
#
# :call-seq:
# convert( name )
# convert { |field| ... }
# convert { |field, field_info| ... }
#
# You can use this method to install a CSV::Converters built-in, or provide a
# block that handles a custom conversion.
#
# If you provide a block that takes one argument, it will be passed the field
# and is expected to return the converted value or the field itself. If your
# block takes two arguments, it will also be passed a CSV::FieldInfo Struct,
# containing details about the field. Again, the block should return a
# converted field or the field itself.
#
def convert(name = nil, &converter)
parser_fields_converter.add_converter(name, &converter)
end
#
# :call-seq:
# header_convert( name )
# header_convert { |field| ... }
# header_convert { |field, field_info| ... }
#
# Identical to CSV#convert(), but for header rows.
#
# Note that this method must be called before header rows are read to have any
# effect.
#
def header_convert(name = nil, &converter)
header_fields_converter.add_converter(name, &converter)
end
include Enumerable
#
# Yields each row of the data source in turn.
#
# Support for Enumerable.
#
# The data source must be open for reading.
#
def each(&block)
parser_enumerator.each(&block)
end
#
# Slurps the remaining rows and returns an Array of Arrays.
#
# The data source must be open for reading.
#
def read
rows = to_a
if parser.use_headers?
Table.new(rows, headers: parser.headers)
else
rows
end
end
alias_method :readlines, :read
# Returns +true+ if the next row read will be a header row.
def header_row?
parser.header_row?
end
#
# The primary read method for wrapped Strings and IOs, a single row is pulled
# from the data source, parsed and returned as an Array of fields (if header
# rows are not used) or a CSV::Row (when header rows are used).
#
# The data source must be open for reading.
#
def shift
if @eof_error
eof_error, @eof_error = @eof_error, nil
raise eof_error
end
begin
parser_enumerator.next
rescue StopIteration
nil
end
end
alias_method :gets, :shift
alias_method :readline, :shift
#
# Returns a simplified description of the key CSV attributes in an
# ASCII compatible String.
#
def inspect
str = ["#<", self.class.to_s, " io_type:"]
# show type of wrapped IO
if @io == $stdout then str << "$stdout"
elsif @io == $stdin then str << "$stdin"
elsif @io == $stderr then str << "$stderr"
else str << @io.class.to_s
end
# show IO.path(), if available
if @io.respond_to?(:path) and (p = @io.path)
str << " io_path:" << p.inspect
end
# show encoding
str << " encoding:" << @encoding.name
# show other attributes
["lineno", "col_sep", "row_sep", "quote_char"].each do |attr_name|
if a = __send__(attr_name)
str << " " << attr_name << ":" << a.inspect
end
end
["skip_blanks", "liberal_parsing"].each do |attr_name|
if a = __send__("#{attr_name}?")
str << " " << attr_name << ":" << a.inspect
end
end
_headers = headers
str << " headers:" << _headers.inspect if _headers
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
private
def determine_encoding(encoding, internal_encoding)
# honor the IO encoding if we can, otherwise default to ASCII-8BIT
io_encoding = raw_encoding
return io_encoding if io_encoding
return Encoding.find(internal_encoding) if internal_encoding
if encoding
encoding, = encoding.split(":", 2) if encoding.is_a?(String)
return Encoding.find(encoding)
end
Encoding.default_internal || Encoding.default_external
end
def normalize_converters(converters)
converters ||= []
unless converters.is_a?(Array)
converters = [converters]
end
converters.collect do |converter|
case converter
when Proc # custom code block
[nil, converter]
else # by name
[converter, nil]
end
end
end
#
# Processes +fields+ with <tt>@converters</tt>, or <tt>@header_converters</tt>
# if +headers+ is passed as +true+, returning the converted field set. Any
# converter that changes the field into something other than a String halts
# the pipeline of conversion for that field. This is primarily an efficiency
# shortcut.
#
def convert_fields(fields, headers = false)
if headers
header_fields_converter.convert(fields, nil, 0)
else
parser_fields_converter.convert(fields, @headers, lineno)
end
end
#
# Returns the encoding of the internal IO object.
#
def raw_encoding
if @io.respond_to? :internal_encoding
@io.internal_encoding || @io.external_encoding
elsif @io.respond_to? :encoding
@io.encoding
else
nil
end
end
def parser_fields_converter
@parser_fields_converter ||= build_parser_fields_converter
end
def build_parser_fields_converter
specific_options = {
builtin_converters: Converters,
}
options = @base_fields_converter_options.merge(specific_options)
build_fields_converter(@initial_converters, options)
end
def header_fields_converter
@header_fields_converter ||= build_header_fields_converter
end
def build_header_fields_converter
specific_options = {
builtin_converters: HeaderConverters,
accept_nil: true,
}
options = @base_fields_converter_options.merge(specific_options)
build_fields_converter(@initial_header_converters, options)
end
def writer_fields_converter
@writer_fields_converter ||= build_writer_fields_converter
end
def build_writer_fields_converter
build_fields_converter(@initial_write_converters,
@write_fields_converter_options)
end
def build_fields_converter(initial_converters, options)
fields_converter = FieldsConverter.new(options)
normalize_converters(initial_converters).each do |name, converter|
fields_converter.add_converter(name, &converter)
end
fields_converter
end
def parser
@parser ||= Parser.new(@io, parser_options)
end
def parser_options
@parser_options.merge(header_fields_converter: header_fields_converter,
fields_converter: parser_fields_converter)
end
def parser_enumerator
@parser_enumerator ||= parser.parse
end
def writer
@writer ||= Writer.new(@io, writer_options)
end
def writer_options
@writer_options.merge(header_fields_converter: header_fields_converter,
fields_converter: writer_fields_converter)
end
end
# Passes +args+ to CSV::instance.
#
# CSV("CSV,data").read
# #=> [["CSV", "data"]]
#
# If a block is given, the instance is passed the block and the return value
# becomes the return value of the block.
#
# CSV("CSV,data") { |c|
# c.read.any? { |a| a.include?("data") }
# } #=> true
#
# CSV("CSV,data") { |c|
# c.read.any? { |a| a.include?("zombies") }
# } #=> false
#
def CSV(*args, &block)
CSV.instance(*args, &block)
end
require_relative "csv/version"
require_relative "csv/core_ext/array"
require_relative "csv/core_ext/string"
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