kotovalexarian-likes-github/ruby--ruby
1
0
Fork 0
mirror of https://github.com/ruby/ruby.git synced 2022-11-09 12:17:21 -05:00
Code Releases Activity

[ruby/csv] More on Recipes headers (#183)

Browse source 
https://github.com/ruby/csv/commit/d7ae3df801
This commit is contained in:
Burdette Lamar 2020-10-09 17:36:03 -05:00 committed by Sutou Kouhei
parent 15e457d6a3
commit 3cfb63fcd8
Notes: git 2020-11-24 09:34:28 +09:00 
Merged: https://github.com/ruby/ruby/pull/3804
1 changed files with 86 additions and 86 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

172
doc/csv/recipes.rdoc
View file

@ -6,62 +6,62 @@ All code snippets on this page assume that the following has been executed:
=== Contents === Contents
- {Parsing: Source Formats}[#label-Parsing-3A+Source+Formats] - {Parsing: Source Formats}[#label-Parsing-3A+Source+Formats]
- {Parse from String}[#label-Parse+from+String] - {Parsing from a String}[#label-Parsing+from+a+String]
- {Parse from String with Headers}[#label-Parse+from+String+with+Headers] - {Recipe: Parse from String with Headers}[#label-Recipe-3A+Parse+from+String+with+Headers]
- {Parse from String Without Headers}[#label-Parse+from+String+Without+Headers] - {Recipe: Parse from String Without Headers}[#label-Recipe-3A+Parse+from+String+Without+Headers]
- {Parse from File}[#label-Parse+from+File] - {Parsing from a File}[#label-Parsing+from+a+File]
- {Parse from File with Headers}[#label-Parse+from+File+with+Headers] - {Recipe: Parse from File with Headers}[#label-Recipe-3A+Parse+from+File+with+Headers]
- {Parse from File Without Headers}[#label-Parse+from+File+Without+Headers] - {Recipe: Parse from File Without Headers}[#label-Recipe-3A+Parse+from+File+Without+Headers]
- {Parse from IO Stream}[#label-Parse+from+IO+Stream] - {Parsing from an IO Stream}[#label-Parsing+from+an+IO+Stream]
- {Parse from IO Stream with Headers}[#label-Parse+from+IO+Stream+with+Headers] - {Recipe: Parse from IO Stream with Headers}[#label-Recipe-3A+Parse+from+IO+Stream+with+Headers]
- {Parse from IO Stream Without Headers}[#label-Parse+from+IO+Stream+Without+Headers] - {Recipe: Parse from IO Stream Without Headers}[#label-Recipe-3A+Parse+from+IO+Stream+Without+Headers]
- {Parsing: Field Converters}[#label-Parsing-3A+Field+Converters] - {Parsing: Field Converters}[#label-Parsing-3A+Field+Converters]
- {Convert Fields to Objects}[#label-Convert+Fields+to+Objects] - {Converting Fields to Objects}[#label-Converting+Fields+to+Objects]
- {Convert Fields to Integers}[#label-Convert+Fields+to+Integers] - {Recipe: Convert Fields to Integers}[#label-Recipe-3A+Convert+Fields+to+Integers]
- {Convert Fields to Floats}[#label-Convert+Fields+to+Floats] - {Recipe: Convert Fields to Floats}[#label-Recipe-3A+Convert+Fields+to+Floats]
- {Convert Fields to Numerics}[#label-Convert+Fields+to+Numerics] - {Recipe: Convert Fields to Numerics}[#label-Recipe-3A+Convert+Fields+to+Numerics]
- {Convert Fields to Dates}[#label-Convert+Fields+to+Dates] - {Recipe: Convert Fields to Dates}[#label-Recipe-3A+Convert+Fields+to+Dates]
- {Convert Fields to DateTimes}[#label-Convert+Fields+to+DateTimes] - {Recipe: Convert Fields to DateTimes}[#label-Recipe-3A+Convert+Fields+to+DateTimes]
- {Convert Assorted Fields to Objects}[#label-Convert+Assorted+Fields+to+Objects] - {Recipe: Convert Assorted Fields to Objects}[#label-Recipe-3A+Convert+Assorted+Fields+to+Objects]
- {Convert Fields to Other Objects}[#label-Convert+Fields+to+Other+Objects] - {Recipe: Convert Fields to Other Objects}[#label-Recipe-3A+Convert+Fields+to+Other+Objects]
- {Filter Field Strings}[#label-Filter+Field+Strings] - {Recipe: Filter Field Strings}[#label-Recipe-3A+Filter+Field+Strings]
- {Register Field Converters}[#label-Register+Field+Converters] - {Recipe: Register Field Converters}[#label-Recipe-3A+Register+Field+Converters]
- {Use Multiple Field Converters}[#label-Use+Multiple+Field+Converters] - {Using Multiple Field Converters}[#label-Using+Multiple+Field+Converters]
- {Specify Multiple Field Converters in Option :converters}[#label-Specify+Multiple+Field+Converters+in+Option+-3Aconverters] - {Recipe: Specify Multiple Field Converters in Option :converters}[#label-Recipe-3A+Specify+Multiple+Field+Converters+in+Option+-3Aconverters]
- {Specify Multiple Field Converters in a Custom Converter List}[#label-Specify+Multiple+Field+Converters+in+a+Custom+Converter+List] - {Recipe: Specify Multiple Field Converters in a Custom Converter List}[#label-Recipe-3A+Specify+Multiple+Field+Converters+in+a+Custom+Converter+List]
- {Generating: Output Formats}[#label-Generating-3A+Output+Formats] - {Generating: Output Formats}[#label-Generating-3A+Output+Formats]
- {Generate to String}[#label-Generate+to+String] - {Generating to a String}[#label-Generating+to+a+String]
- {Generate to String with Headers}[#label-Generate+to+String+with+Headers] - {Recipe: Generate to String with Headers}[#label-Recipe-3A+Generate+to+String+with+Headers]
- {Generate to String Without Headers}[#label-Generate+to+String+Without+Headers] - {Recipe: Generate to String Without Headers}[#label-Recipe-3A+Generate+to+String+Without+Headers]
- {Generate to File}[#label-Generate+to+File] - {Generating to a File}[#label-Generating+to+a+File]
- {Generate to File with Headers}[#label-Generate+to+File+with+Headers] - {Recipe: Generate to File with Headers}[#label-Recipe-3A+Generate+to+File+with+Headers]
- {Generate to File Without Headers}[#label-Generate+to+File+Without+Headers] - {Recipe: Generate to File Without Headers}[#label-Recipe-3A+Generate+to+File+Without+Headers]
- {Generate to IO Stream}[#label-Generate+to+IO+Stream] - {Generating to IO an Stream}[#label-Generating+to+an+IO+Stream]
- {Generate to IO Stream with Headers}[#label-Generate+to+IO+Stream+with+Headers] - {Recipe: Generate to IO Stream with Headers}[#label-Recipe-3A+Generate+to+IO+Stream+with+Headers]
- {Generate to IO Stream Without Headers}[#label-Generate+to+IO+Stream+Without+Headers] - {Recipe: Generate to IO Stream Without Headers}[#label-Recipe-3A+Generate+to+IO+Stream+Without+Headers]
- {Filtering: Source and Output Formats}[#label-Filtering-3A+Source+and+Output+Formats] - {Filtering: Source and Output Formats}[#label-Filtering-3A+Source+and+Output+Formats]
- {Filter String to String}[#label-Filter+String+to+String] - {Filtering String to String}[#label-Filtering+String+to+String]
- {Filter String to String with Headers}[#label-Filter+String+to+String+with+Headers] - {Recipe: Filter String to String with Headers}[#label-Recipe-3A+Filter+String+to+String+with+Headers]
- {Filter String to String Without Headers}[#label-Filter+String+to+String+Without+Headers] - {Recipe: Filter String to String Without Headers}[#label-Recipe-3A+Filter+String+to+String+Without+Headers]
- {Filter String to IO Stream}[#label-Filter+String+to+IO+Stream] - {Filtering String to IO Stream}[#label-Filtering+String+to+IO+Stream]
- {Filter String to IO Stream with Headers}[#label-Filter+String+to+IO+Stream+with+Headers] - {Recipe: Filter String to IO Stream with Headers}[#label-Recipe-3A+Filter+String+to+IO+Stream+with+Headers]
- {Filter String to IO Stream Without Headers}[#label-Filter+String+to+IO+Stream+Without+Headers] - {Recipe: Filter String to IO Stream Without Headers}[#label-Recipe-3A+Filter+String+to+IO+Stream+Without+Headers]
- {Filter IO Stream to String}[#label-Filter+IO+Stream+to+String] - {Filtering IO Stream to String}[#label-Filtering+IO+Stream+to+String]
- {Filter IO Stream to String with Headers}[#label-Filter+IO+Stream+to+String+with+Headers] - {Recipe: Filter IO Stream to String with Headers}[#label-Recipe-3A+Filter+IO+Stream+to+String+with+Headers]
- {Filter IO Stream to String Without Headers}[#label-Filter+IO+Stream+to+String+Without+Headers] - {Recipe: Filter IO Stream to String Without Headers}[#label-Recipe-3A+Filter+IO+Stream+to+String+Without+Headers]
- {Filter IO Stream to IO Stream}[#label-Filter+IO+Stream+to+IO+Stream] - {Filtering IO Stream to IO Stream}[#label-Filtering+IO+Stream+to+IO+Stream]
- {Filter IO Stream to IO Stream with Headers}[#label-Filter+IO+Stream+to+IO+Stream+with+Headers] - {Recipe: Filter IO Stream to IO Stream with Headers}[#label-Recipe-3A+Filter+IO+Stream+to+IO+Stream+with+Headers]
- {Filter IO Stream to IO Stream Without Headers}[#label-Filter+IO+Stream+to+IO+Stream+Without+Headers] - {Recipe: Filter IO Stream to IO Stream Without Headers}[#label-Recipe-3A+Filter+IO+Stream+to+IO+Stream+Without+Headers]
=== Parsing: Source Formats === Parsing: Source Formats
You can parse \CSV data from a \String, from a \File (via its path), or from an \IO stream. You can parse \CSV data from a \String, from a \File (via its path), or from an \IO stream.
==== Parse from \String ==== Parsing from a \String
You can parse \CSV data from a \String, with or without headers. You can parse \CSV data from a \String, with or without headers.
===== Parse from \String with Headers ===== Recipe: Parse from \String with Headers
Use class method CSV.parse with option +headers+ to read a source \String all at once Use class method CSV.parse with option +headers+ to read a source \String all at once
(may have memory resource implications): (may have memory resource implications):
@ -77,7 +77,7 @@ Ouput:
#<CSV::Row "Name":"bar" "Value":"1"> #<CSV::Row "Name":"bar" "Value":"1">
#<CSV::Row "Name":"baz" "Value":"2"> #<CSV::Row "Name":"baz" "Value":"2">
===== Parse from \String Without Headers ===== Recipe: Parse from \String Without Headers
Use class method CSV.parse without option +headers+ to read a source \String all at once Use class method CSV.parse without option +headers+ to read a source \String all at once
(may have memory resource implications): (may have memory resource implications):
@ -93,11 +93,11 @@ Output:
["bar", "1"] ["bar", "1"]
["baz", "2"] ["baz", "2"]
==== Parse from \File ==== Parsing from a \File
You can parse \CSV data from a \File, with or without headers. You can parse \CSV data from a \File, with or without headers.
===== Parse from \File with Headers ===== Recipe: Parse from \File with Headers
Use instance method CSV#read with option +headers+ to read a file all at once: Use instance method CSV#read with option +headers+ to read a file all at once:
string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n"
@ -114,7 +114,7 @@ Output:
#<CSV::Row "Name":"bar" "Value":"1"> #<CSV::Row "Name":"bar" "Value":"1">
#<CSV::Row "Name":"baz" "Value":"2"> #<CSV::Row "Name":"baz" "Value":"2">
===== Parse from \File Without Headers ===== Recipe: Parse from \File Without Headers
Use class method CSV.read without option +headers+ to read a file all at once: Use class method CSV.read without option +headers+ to read a file all at once:
string = "foo,0\nbar,1\nbaz,2\n" string = "foo,0\nbar,1\nbaz,2\n"
@ -131,11 +131,11 @@ Output:
["bar", "1"] ["bar", "1"]
["baz", "2"] ["baz", "2"]
==== Parse from \IO Stream ==== Parsing from an \IO Stream
You can parse \CSV data from an \IO stream, with or without headers. You can parse \CSV data from an \IO stream, with or without headers.
===== Parse from \IO Stream with Headers ===== Recipe: Parse from \IO Stream with Headers
Use class method CSV.parse with option +headers+ to read an \IO stream all at once: Use class method CSV.parse with option +headers+ to read an \IO stream all at once:
string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n"
@ -156,7 +156,7 @@ Output:
#<CSV::Row "Name":"bar" "Value":"1"> #<CSV::Row "Name":"bar" "Value":"1">
#<CSV::Row "Name":"baz" "Value":"2"> #<CSV::Row "Name":"baz" "Value":"2">
===== Parse from \IO Stream Without Headers ===== Recipe: Parse from \IO Stream Without Headers
Use class method CSV.parse without option +headers+ to read an \IO stream all at once: Use class method CSV.parse without option +headers+ to read an \IO stream all at once:
string = "foo,0\nbar,1\nbaz,2\n" string = "foo,0\nbar,1\nbaz,2\n"
@ -182,7 +182,7 @@ Output:
You can use field converters to change parsed \String fields into other objects, You can use field converters to change parsed \String fields into other objects,
or to otherwise modify the \String fields. or to otherwise modify the \String fields.
==== Convert Fields to Objects ==== Converting Fields to Objects
Use field converters to change parsed \String objects into other, more specific, objects. Use field converters to change parsed \String objects into other, more specific, objects.
@ -198,49 +198,49 @@ Other built-in field converters include:
You can also define field converters to convert to objects of other classes. You can also define field converters to convert to objects of other classes.
===== Convert Fields to Integers ===== Recipe: Convert Fields to Integers
Convert fields to \Integer objects using built-in converter <tt>:integer</tt>: Convert fields to \Integer objects using built-in converter <tt>:integer</tt>:
source = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" source = "Name,Value\nfoo,0\nbar,1\nbaz,2\n"
parsed = CSV.parse(source, headers: true, converters: :integer) parsed = CSV.parse(source, headers: true, converters: :integer)
parsed.map {|row| row['Value'].class} # => [Integer, Integer, Integer] parsed.map {|row| row['Value'].class} # => [Integer, Integer, Integer]
===== Convert Fields to Floats ===== Recipe: Convert Fields to Floats
Convert fields to \Float objects using built-in converter <tt>:float</tt>: Convert fields to \Float objects using built-in converter <tt>:float</tt>:
source = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" source = "Name,Value\nfoo,0\nbar,1\nbaz,2\n"
parsed = CSV.parse(source, headers: true, converters: :float) parsed = CSV.parse(source, headers: true, converters: :float)
parsed.map {|row| row['Value'].class} # => [Float, Float, Float] parsed.map {|row| row['Value'].class} # => [Float, Float, Float]
===== Convert Fields to Numerics ===== Recipe: Convert Fields to Numerics
Convert fields to \Integer and \Float objects using built-in converter <tt>:numeric</tt>: Convert fields to \Integer and \Float objects using built-in converter <tt>:numeric</tt>:
source = "Name,Value\nfoo,0\nbar,1.1\nbaz,2.2\n" source = "Name,Value\nfoo,0\nbar,1.1\nbaz,2.2\n"
parsed = CSV.parse(source, headers: true, converters: :numeric) parsed = CSV.parse(source, headers: true, converters: :numeric)
parsed.map {|row| row['Value'].class} # => [Integer, Float, Float] parsed.map {|row| row['Value'].class} # => [Integer, Float, Float]
===== Convert Fields to Dates ===== Recipe: Convert Fields to Dates
Convert fields to \Date objects using built-in converter <tt>:date</tt>: Convert fields to \Date objects using built-in converter <tt>:date</tt>:
source = "Name,Date\nfoo,2001-02-03\nbar,2001-02-04\nbaz,2001-02-03\n" source = "Name,Date\nfoo,2001-02-03\nbar,2001-02-04\nbaz,2001-02-03\n"
parsed = CSV.parse(source, headers: true, converters: :date) parsed = CSV.parse(source, headers: true, converters: :date)
parsed.map {|row| row['Date'].class} # => [Date, Date, Date] parsed.map {|row| row['Date'].class} # => [Date, Date, Date]
===== Convert Fields to DateTimes ===== Recipe: Convert Fields to DateTimes
Convert fields to \DateTime objects using built-in converter <tt>:date_time</tt>: Convert fields to \DateTime objects using built-in converter <tt>:date_time</tt>:
source = "Name,DateTime\nfoo,2001-02-03\nbar,2001-02-04\nbaz,2020-05-07T14:59:00-05:00\n" source = "Name,DateTime\nfoo,2001-02-03\nbar,2001-02-04\nbaz,2020-05-07T14:59:00-05:00\n"
parsed = CSV.parse(source, headers: true, converters: :date_time) parsed = CSV.parse(source, headers: true, converters: :date_time)
parsed.map {|row| row['DateTime'].class} # => [DateTime, DateTime, DateTime] parsed.map {|row| row['DateTime'].class} # => [DateTime, DateTime, DateTime]
===== Convert Assorted Fields to Objects ===== Recipe: Convert Assorted Fields to Objects
Convert assorted fields to objects using built-in converter <tt>:all</tt>: Convert assorted fields to objects using built-in converter <tt>:all</tt>:
source = "Type,Value\nInteger,0\nFloat,1.0\nDateTime,2001-02-04\n" source = "Type,Value\nInteger,0\nFloat,1.0\nDateTime,2001-02-04\n"
parsed = CSV.parse(source, headers: true, converters: :all) parsed = CSV.parse(source, headers: true, converters: :all)
parsed.map {|row| row['Value'].class} # => [Integer, Float, DateTime] parsed.map {|row| row['Value'].class} # => [Integer, Float, DateTime]
===== Convert Fields to Other Objects ===== Recipe: Convert Fields to Other Objects
Define a custom field converter to convert \String fields into other objects. Define a custom field converter to convert \String fields into other objects.
This example defines and uses a custom field converter This example defines and uses a custom field converter
@ -252,7 +252,7 @@ that converts each column-1 value to a \Rational object:
parsed = CSV.parse(source, headers: true, converters: rational_converter) parsed = CSV.parse(source, headers: true, converters: rational_converter)
parsed.map {|row| row['Value'].class} # => [Rational, Rational, Rational] parsed.map {|row| row['Value'].class} # => [Rational, Rational, Rational]
==== Filter Field Strings ==== Recipe: Filter Field Strings
Define a custom field converter to modify \String fields. Define a custom field converter to modify \String fields.
This example defines and uses a custom field converter This example defines and uses a custom field converter
@ -263,7 +263,7 @@ that strips whitespace from each field value:
parsed['Name'] # => ["foo", "bar", "baz"] parsed['Name'] # => ["foo", "bar", "baz"]
parsed['Value'] # => ["0", "1", "2"] parsed['Value'] # => ["0", "1", "2"]
==== Register Field Converters ==== Recipe: Register Field Converters
Register a custom field converter, assigning it a name; Register a custom field converter, assigning it a name;
then refer to the converter by its name: then refer to the converter by its name:
@ -272,20 +272,20 @@ then refer to the converter by its name:
parsed = CSV.parse(source, headers: true, converters: :rational) parsed = CSV.parse(source, headers: true, converters: :rational)
parsed['Value'] # => [(0/1), (1/1), (2/1)] parsed['Value'] # => [(0/1), (1/1), (2/1)]
==== Use Multiple Field Converters ==== Using Multiple Field Converters
You can use multiple field converters in either of these ways: You can use multiple field converters in either of these ways:
- Specify converters in option <tt>:converters</tt>. - Specify converters in option <tt>:converters</tt>.
- Specify converters in a custom converter list. - Specify converters in a custom converter list.
===== Specify Multiple Field Converters in Option <tt>:converters</tt> ===== Recipe: Specify Multiple Field Converters in Option <tt>:converters</tt>
Apply multiple field converters by specifying them in option <tt>:conveters</tt>: Apply multiple field converters by specifying them in option <tt>:conveters</tt>:
source = "Name,Value\nfoo,0\nbar,1.0\nbaz,2.0\n" source = "Name,Value\nfoo,0\nbar,1.0\nbaz,2.0\n"
parsed = CSV.parse(source, headers: true, converters: [:integer, :float]) parsed = CSV.parse(source, headers: true, converters: [:integer, :float])
parsed['Value'] # => [0, 1.0, 2.0] parsed['Value'] # => [0, 1.0, 2.0]
===== Specify Multiple Field Converters in a Custom Converter List ===== Recipe: Specify Multiple Field Converters in a Custom Converter List
Apply multiple field converters by defining and registering a custom converter list: Apply multiple field converters by defining and registering a custom converter list:
strip_converter = proc {|field| field.strip } strip_converter = proc {|field| field.strip }
@ -300,11 +300,11 @@ Apply multiple field converters by defining and registering a custom converter l
You can generate \CSV output to a \String, to a \File (via its path), or to an \IO stream. You can generate \CSV output to a \String, to a \File (via its path), or to an \IO stream.
==== Generate to \String ==== Generating to a \String
You can generate \CSV output to a \String, with or without headers. You can generate \CSV output to a \String, with or without headers.
===== Generate to \String with Headers ===== Recipe: Generate to \String with Headers
Use class method CSV.generate with option +headers+ to generate to a \String. Use class method CSV.generate with option +headers+ to generate to a \String.
@ -317,7 +317,7 @@ that are to be generated:
end end
output_string # => "Name,Value\nFoo,0\nBar,1\nBaz,2\n" output_string # => "Name,Value\nFoo,0\nBar,1\nBaz,2\n"
===== Generate to \String Without Headers ===== Recipe: Generate to \String Without Headers
Use class method CSV.generate without option +headers+ to generate to a \String. Use class method CSV.generate without option +headers+ to generate to a \String.
@ -330,11 +330,11 @@ that are to be generated:
end end
output_string # => "Foo,0\nBar,1\nBaz,2\n" output_string # => "Foo,0\nBar,1\nBaz,2\n"
==== Generate to \File ==== Generating to a \File
You can generate /CSV data to a \File, with or without headers. You can generate /CSV data to a \File, with or without headers.
===== Generate to \File with Headers ===== Recipe: Generate to \File with Headers
Use class method CSV.open with option +headers+ generate to a \File. Use class method CSV.open with option +headers+ generate to a \File.
@ -348,7 +348,7 @@ that are to be generated:
end end
p File.read(path) # => "Name,Value\nFoo,0\nBar,1\nBaz,2\n" p File.read(path) # => "Name,Value\nFoo,0\nBar,1\nBaz,2\n"
===== Generate to \File Without Headers ===== Recipe: Generate to \File Without Headers
Use class method CSV.open without option +headers+ to generate to a \File. Use class method CSV.open without option +headers+ to generate to a \File.
@ -362,11 +362,11 @@ that are to be generated:
end end
p File.read(path) # => "Foo,0\nBar,1\nBaz,2\n" p File.read(path) # => "Foo,0\nBar,1\nBaz,2\n"
==== Generate to \IO Stream ==== Generating to an \IO Stream
You can generate \CSV data to an \IO stream, with or without headers. You can generate \CSV data to an \IO stream, with or without headers.
==== Generate to \IO Stream with Headers ==== Recipe: Generate to \IO Stream with Headers
Use class method CSV.new with option +headers+ to generate \CSV data to an \IO stream: Use class method CSV.new with option +headers+ to generate \CSV data to an \IO stream:
path = 't.csv' path = 't.csv'
@ -378,7 +378,7 @@ Use class method CSV.new with option +headers+ to generate \CSV data to an \IO s
end end
p File.read(path) # => "Name,Value\nFoo,0\nBar,1\nBaz,2\n" p File.read(path) # => "Name,Value\nFoo,0\nBar,1\nBaz,2\n"
===== Generate to \IO Stream Without Headers ===== Recipe: Generate to \IO Stream Without Headers
Use class method CSV.new without option +headers+ to generate \CSV data to an \IO stream: Use class method CSV.new without option +headers+ to generate \CSV data to an \IO stream:
path = 't.csv' path = 't.csv'
@ -396,11 +396,11 @@ You can use a Unix-style "filter" for \CSV data.
The filter reads source \CSV data and writes output \CSV data as modified by the filter. The filter reads source \CSV data and writes output \CSV data as modified by the filter.
The input and output \CSV data may be any mixture of \Strings and \IO streams. The input and output \CSV data may be any mixture of \Strings and \IO streams.
==== Filter \String to \String ==== Filtering \String to \String
You can filter one \String to another, with or without headers. You can filter one \String to another, with or without headers.
===== Filter \String to \String with Headers ===== Recipe: Filter \String to \String with Headers
Use class method CSV.filter with option +headers+ to filter a \String to another \String: Use class method CSV.filter with option +headers+ to filter a \String to another \String:
in_string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" in_string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n"
@ -411,7 +411,7 @@ Use class method CSV.filter with option +headers+ to filter a \String to another
end end
out_string # => "Name,Value\nFOO,0000\nBAR,1111\nBAZ,2222\n" out_string # => "Name,Value\nFOO,0000\nBAR,1111\nBAZ,2222\n"
===== Filter \String to \String Without Headers ===== Recipe: Filter \String to \String Without Headers
Use class method CSV.filter without option +headers+ to filter a \String to another \String: Use class method CSV.filter without option +headers+ to filter a \String to another \String:
in_string = "foo,0\nbar,1\nbaz,2\n" in_string = "foo,0\nbar,1\nbaz,2\n"
@ -422,11 +422,11 @@ Use class method CSV.filter without option +headers+ to filter a \String to anot
end end
out_string # => "FOO,0000\nBAR,1111\nBAZ,2222\n" out_string # => "FOO,0000\nBAR,1111\nBAZ,2222\n"
==== Filter \String to \IO Stream ==== Filtering \String to \IO Stream
You can filter a \String to an \IO stream, with or without headers. You can filter a \String to an \IO stream, with or without headers.
===== Filter \String to \IO Stream with Headers ===== Recipe: Filter \String to \IO Stream with Headers
Use class method CSV.filter with option +headers+ to filter a \String to an \IO stream: Use class method CSV.filter with option +headers+ to filter a \String to an \IO stream:
in_string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" in_string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n"
@ -439,7 +439,7 @@ Use class method CSV.filter with option +headers+ to filter a \String to an \IO
end end
p File.read(path) # => "Name,Value\nFOO,0000\nBAR,1111\nBAZ,2222\n" p File.read(path) # => "Name,Value\nFOO,0000\nBAR,1111\nBAZ,2222\n"
===== Filter \String to \IO Stream Without Headers ===== Recipe: Filter \String to \IO Stream Without Headers
Use class method CSV.filter without option +headers+ to filter a \String to an \IO stream: Use class method CSV.filter without option +headers+ to filter a \String to an \IO stream:
in_string = "foo,0\nbar,1\nbaz,2\n" in_string = "foo,0\nbar,1\nbaz,2\n"
@ -452,11 +452,11 @@ Use class method CSV.filter without option +headers+ to filter a \String to an \
end end
p File.read(path) # => "FOO,0000\nBAR,1111\nBAZ,2222\n" p File.read(path) # => "FOO,0000\nBAR,1111\nBAZ,2222\n"
==== Filter \IO Stream to \String ==== Filtering \IO Stream to \String
You can filter an \IO stream to a \String, with or without headers. You can filter an \IO stream to a \String, with or without headers.
===== Filter \IO Stream to \String with Headers ===== Recipe: Filter \IO Stream to \String with Headers
Use class method CSV.filter with option +headers+ to filter an \IO stream to a \String: Use class method CSV.filter with option +headers+ to filter an \IO stream to a \String:
in_string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n" in_string = "Name,Value\nfoo,0\nbar,1\nbaz,2\n"
@ -471,7 +471,7 @@ Use class method CSV.filter with option +headers+ to filter an \IO stream to a \
end end
out_string # => "Name,Value\nFOO,0000\nBAR,1111\nBAZ,2222\n" out_string # => "Name,Value\nFOO,0000\nBAR,1111\nBAZ,2222\n"
===== Filter \IO Stream to \String Without Headers ===== Recipe: Filter \IO Stream to \String Without Headers
Use class method CSV.filter without option +headers+ to filter an \IO stream to a \String: Use class method CSV.filter without option +headers+ to filter an \IO stream to a \String:
in_string = "foo,0\nbar,1\nbaz,2\n" in_string = "foo,0\nbar,1\nbaz,2\n"
@ -486,11 +486,11 @@ Use class method CSV.filter without option +headers+ to filter an \IO stream to
end end
out_string # => "FOO,0000\nBAR,1111\nBAZ,2222\n" out_string # => "FOO,0000\nBAR,1111\nBAZ,2222\n"
==== Filter \IO Stream to \IO Stream ==== Filtering \IO Stream to \IO Stream
You can filter an \IO stream to another \IO stream, with or without headers. You can filter an \IO stream to another \IO stream, with or without headers.
===== Filter \IO Stream to \IO Stream with Headers ===== Recipe: Filter \IO Stream to \IO Stream with Headers
Use class method CSV.filter with option +headers+ to filter an \IO stream to another \IO stream: Use class method CSV.filter with option +headers+ to filter an \IO stream to another \IO stream:
in_path = 't.csv' in_path = 't.csv'
@ -507,7 +507,7 @@ Use class method CSV.filter with option +headers+ to filter an \IO stream to ano
end end
p File.read(out_path) # => "Name,Value\nFOO,0000\nBAR,1111\nBAZ,2222\n" p File.read(out_path) # => "Name,Value\nFOO,0000\nBAR,1111\nBAZ,2222\n"
===== Filter \IO Stream to \IO Stream Without Headers ===== Recipe: Filter \IO Stream to \IO Stream Without Headers
Use class method CSV.filter without option +headers+ to filter an \IO stream to another \IO stream: Use class method CSV.filter without option +headers+ to filter an \IO stream to another \IO stream:
in_path = 't.csv' in_path = 't.csv'