Class: CsvHashReader

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Enumerable
Defined in:
lib/csvreader/base.rb,
lib/csvreader/builder.rb,
lib/csvreader/reader_hash.rb

Defined Under Namespace

Classes: Builder

Constant Summary collapse

DEFAULT =

pre-define CsvReader (built-in) formats/dialect

Builder.new( Parser::DEFAULT )
NUMERIC = 
Builder.new( Parser::NUMERIC )
STRICT = 
Builder.new( Parser::STRICT )
RFC4180 = 
Builder.new( Parser::RFC4180 )
EXCEL = 
Builder.new( Parser::EXCEL )
MYSQL = 
Builder.new( Parser::MYSQL )
POSTGRES = 
POSTGRESQL           = Builder.new( Parser::POSTGRESQL )
POSTGRES_TEXT = 
POSTGRESQL_TEXT = Builder.new( Parser::POSTGRESQL_TEXT )
TAB = 
Builder.new( Parser::TAB )
FIXED = 
Builder.new( Parser::FIXED )
Parser =

add convenience shortcuts / aliases for CsvReader support classes

CsvReader::Parser
ParserFixed = 
CsvReader::ParserFixed
Converter = 
CsvReader::Converter

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(data, headers: nil, sep: nil, converters: nil, header_converters: nil, width: nil, parser: nil) ⇒ CsvHashReader

Returns a new instance of CsvHashReader.

Raises:

  • (ArgumentError) 


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# File 'lib/csvreader/reader_hash.rb', line 114

def initialize( data, headers: nil, sep: nil,
                      converters: nil,
                      header_converters: nil,
                      width: nil,
                      parser: nil )
      raise ArgumentError.new( "Cannot parse nil as CSV" )  if data.nil?
      ## todo: use (why? why not) - raise ArgumentError, "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

      ## pass in headers as array e.g. ['A', 'B', 'C']
      ##  double check: run header_converters on passed in headers?
      ##    for now - do NOT auto-convert passed in headers - keep them as-is (1:1)
      @names = headers ? headers : nil

      @sep   = sep
      @width = width

      @converters        = Converter.create_converters( converters )
      @header_converters = Converter.create_header_converters( header_converters )

      @parser = parser.nil? ? Parser::DEFAULT : parser
end

Class Method Details

.default ⇒ Object

alternative alias for DEFAULT



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# File 'lib/csvreader/base.rb', line 147

def self.default()         DEFAULT;         end

.excel ⇒ Object

alternative alias for EXCEL



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# File 'lib/csvreader/base.rb', line 153

def self.excel()           EXCEL;           end

.f ⇒ Object 



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# File 'lib/csvreader/base.rb', line 162

def self.f()               fixed;           end

.fix ⇒ Object 



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# File 'lib/csvreader/base.rb', line 161

def self.fix()             fixed;           end

.fixed ⇒ Object 



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# File 'lib/csvreader/base.rb', line 160

def self.fixed()           FIXED;           end

.foreach(path, headers: nil, sep: nil, converters: nil, header_converters: nil, width: nil, parser: nil, &block) ⇒ Object 



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# File 'lib/csvreader/reader_hash.rb', line 60

def self.foreach( path, headers: nil,
                        sep: nil,
                        converters: nil,
                        header_converters: nil,
                        width: nil,
                        parser: nil, &block )
  csv = open( path,
              headers: headers,
              sep: sep,
              converters: converters,
              header_converters: header_converters,
              width: width,
              parser: parser )

  if block_given?
    begin
      csv.each( &block )
    ensure
      csv.close
    end
  else
    csv.to_enum    ## note: caller (responsible) must close file!!!
    ## remove version without block given - why? why not?
    ## use Csv.open().to_enum  or Csv.open().each
    ##   or Csv.new( File.new() ).to_enum or Csv.new( File.new() ).each ???
  end
end

.mysql ⇒ Object 



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# File 'lib/csvreader/base.rb', line 154

def self.mysql()           MYSQL;           end

.n ⇒ Object 



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# File 'lib/csvreader/base.rb', line 150

def self.n()               numeric;         end

.num ⇒ Object 



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# File 'lib/csvreader/base.rb', line 149

def self.num()             numeric;         end

.numeric ⇒ Object 



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# File 'lib/csvreader/base.rb', line 148

def self.numeric()         NUMERIC;         end

.open(path, mode = nil, headers: nil, sep: nil, converters: nil, header_converters: nil, width: nil, parser: nil, &block) ⇒ Object 



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# File 'lib/csvreader/reader_hash.rb', line 13

def self.open( path, mode=nil,
               headers: nil,
               sep: nil,
               converters: nil,
               header_converters: nil,
               width: nil,
               parser: nil, &block )   ## rename path to filename or name - why? why not?

    ## note: default mode (if nil/not passed in) to 'r:bom|utf-8'
    f = File.open( path, mode ? mode : 'r:bom|utf-8' )
    csv = new(f, headers: headers,
                 sep: sep,
                 converters: converters,
                 header_converters: header_converters,
                 width: width,
                 parser: parser )

    # handle blocks like Ruby's open(), not like the (old old) CSV library
    if block_given?
      begin
        block.call( csv )
      ensure
        csv.close
      end
    else
      csv
    end
end

.parse(data, headers: nil, sep: nil, converters: nil, header_converters: nil, width: nil, parser: nil, &block) ⇒ Object 



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# File 'lib/csvreader/reader_hash.rb', line 89

def self.parse( data, headers: nil,
                      sep: nil,
                      converters: nil,
                      header_converters: nil,
                      width: nil,
                      parser: nil, &block )
  csv = new( data,
             headers: headers,
             sep: sep,
             converters: converters,
             header_converters: header_converters,
             width: width,
             parser: parser )

  if block_given?
    csv.each( &block )  ## note: caller (responsible) must close file!!! - add autoclose - why? why not?
  else  # slurp contents, if no block is given
    csv.read            ## note: caller (responsible) must close file!!! - add autoclose - why? why not?
  end
end

.postgres ⇒ Object 



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# File 'lib/csvreader/base.rb', line 156

def self.postgres()        postgresql;      end

.postgres_text ⇒ Object 



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# File 'lib/csvreader/base.rb', line 158

def self.postgres_text()   postgresql_text; end

.postgresql ⇒ Object 



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# File 'lib/csvreader/base.rb', line 155

def self.postgresql()      POSTGRESQL;      end

.postgresql_text ⇒ Object 



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# File 'lib/csvreader/base.rb', line 157

def self.postgresql_text() POSTGRESQL_TEXT; end

.read(path, headers: nil, sep: nil, converters: nil, header_converters: nil, width: nil, parser: nil) ⇒ Object 



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# File 'lib/csvreader/reader_hash.rb', line 43

def self.read( path, headers: nil,
                     sep: nil,
                     converters: nil,
                     header_converters: nil,
                     width: nil,
                     parser: nil )
    open( path,
          headers: headers,
          sep: sep,
          converters: converters,
          header_converters: header_converters,
          width: width,
          parser: parser ) { |csv| csv.read }
end

.rfc4180 ⇒ Object

alternative alias for RFC4180



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# File 'lib/csvreader/base.rb', line 152

def self.rfc4180()         RFC4180;         end

.strict ⇒ Object

alternative alias for STRICT



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# File 'lib/csvreader/base.rb', line 151

def self.strict()          STRICT;          end

.tab ⇒ Object 



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# File 'lib/csvreader/base.rb', line 159

def self.tab()             TAB;             end

Instance Method Details

#each(&block) ⇒ Object 



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# File 'lib/csvreader/reader_hash.rb', line 158

def each( &block )

  ## todo/fix:
  ##   add case for headers/names.size != values.size
  ##   - add rest option? for if less headers than values (see python csv.DictReader - why? why not?)
  ##
  ##   handle case with duplicate and empty header names etc.


  if block_given?
    kwargs = {}
    ## note: only add separator if present/defined (not nil)
    ##  todo/fix: change sep keyword to "known" classes!!!!
    kwargs[:sep] = @sep    if @sep && @parser.respond_to?( :'sep=' )

    kwargs[:width] = @width  if @parser.is_a?( ParserFixed )


    @parser.parse( @io, kwargs ) do |raw_values|     # sep: sep
       if @names.nil?    ## check for (first) headers row
         if @header_converters.empty?
           @names = raw_values   ## store header row / a.k.a. field/column names
         else
           values = []
           raw_values.each_with_index do |value,i|
             values << @header_converters.convert( value, i )
           end
           @names = values
         end
       else    ## "regular" record
         raw_record = @names.zip( raw_values ).to_h    ## todo/fix: check for more values than names/headers!!!
         if @converters.empty?
           block.call( raw_record )
         else
           ## add "post"-processing with converters pipeline
           ##   that is, convert all strings to integer, float, date, ... if wanted
           record = {}
           raw_record.each do | key, value |
             record[ key ] = @converters.convert( value, key )
           end
           block.call( record )
         end
       end
    end
  else
    to_enum
  end
end

#read ⇒ Object

method each



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# File 'lib/csvreader/reader_hash.rb', line 207

def read() to_a; end