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CSV::Parser zef:tony-o last updated on 2023-06-06



CSV::Parser - parses binary CSV file and reads it line by line.


This module is pretty badass. It reads CSV files line by line and can handle individual lines so you can handle your own file reads or you can let me do the damn work for you. It handles binary files with relative ease so you can parse your binary 'Comma Separated Value' files like a pro.

use CSV::Parser;

my $file_handle = open 'some.csv', :r;
my $parser =

# Option 1
until $file_handle.eof {
  my %data = %($parser.get_line());
  # do something here with your hashish data


# Option 2
my %data;
while %data = %($parser.get_line()) {
  # do something with data here

$file_handle.close; # don't forget to close


$ zef install CSV::Parser


method new

method new(
    IO::Handle :$file_handle,
    Bool       :$binary,
    Bool       :$contains_header_row,
    int        :$chunk_size,

Constructs a CSV parser and sets its attributes to the provided options.


File handle opened with read.


Indicates if file was opened in binary mode. If True, the file was opened as binary and all operator/separator options are REQUIRED to be passed as Buf objects (instead of Str).


Indicates if the first line should be intepreted as column names. If False, the first line won't be interpreted as column names and each parsed line will be returned as a hash with keys 0..X-1, where X is the number of columns. If True, the first line will be interpreted as column names, and each subsequent line will be returned as a hash whose keys are the column names.


A Callable with signature ($key, $value, :$header = False) to normalize the key-value pair for each CSV row. The $key is the header value if available, otherwise the column index. The $value is the value of the column. The $header boolean flag indicates whether we're parsing a header or a row value. The return value is the column's final value, i.e., a Str.


Specifies a single-character string used as the the column separator for each row.


Specifies the separator between CSV rows. See field_separator - this will be included in a parsed value if found in an open field_operator.


Specifies the character [sequence] used to escape a field (can handle line_separator encapsulation). See field_separator.


Specifies the single-character string used to escape strings in a CSV row. See field_separator.


Specifies how many bytes to read from the file handle. It can be increased to improve performance if you are parsing some huge lined binary file. 1024 should be sufficient.

method headers

Returns the parsed headers, if available.

method get_line

method get_line()

Reads a line or chunk from a file and return the parsed line. If this is the first call to this function and contains_header_row is set then this will parse the first 2 lines and use the first row's values as the column values.

method parse

method parse($line, :$header = False) returns Hash

Parses a Str or Buf in accordance with the options set in new. Set the binary flag in new if you are going to pass a Buf.

method reset

method reset()

Closes and re-opens the file handle provided in new.




Copyright 2023 tony-o

This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.