ya-csv v1.0.0
ya-csv
Event based CSV parser and writer for Node.js suitable for processing large CSV streams.
- Designed for high performance and ease of use.
- RFC 4180 compliance with optional extensions.
- Zero dependencies.
Example
// A simple echo program:
var csv = require('ya-csv');
var reader = csv.createCsvStreamReader(process.openStdin());
var writer = csv.createCsvStreamWriter(process.stdout);
reader.addListener('data', function(data) {
writer.writeRecord(data);
});
reader.addListener('error', function(e) {
console.error('Oops!');
});
Installation
npm install ya-csv
Current version requires at least Node.js v0.2.3 and it's tested with Node.js v0.4.12, 0.6.11, 0.7.5 and v0.10.24. Hope it works with the other versions in between too.
Features
- event based, suitable for processing big CSV streams
- configurable separator, quote and escape characters (comma, double-quote and double-quote by default)
- ignores lines starting with configurable comment character (off by default)
- supports memory-only streaming
More examples
Echo first column of the data.csv
file:
// equivalent of csv.createCsvFileReader('data.csv')
var reader = csv.createCsvFileReader('data.csv', {
'separator': ',',
'quote': '"',
'escape': '"',
'comment': '',
});
var writer = new csv.CsvWriter(process.stdout);
reader.addListener('data', function(data) {
writer.writeRecord([ data[0] ]);
});
Return data in objects rather than arrays: either by grabbing the column names from the header row (first row is not passed to the data
listener):
var reader = csv.createCsvFileReader('data.csv', { columnsFromHeader: true });
reader.addListener('data', function(data) {
// supposing there are so named columns in the source file
sys.puts(data.col1 + " ... " + data.col2);
});
... or by providing column names from the client code (first row is passed to the data
listener in this case):
var reader = csv.createCsvFileReader('data.csv');
reader.setColumnNames([ 'col1', 'col2' ]);
reader.addListener('data', function(data) {
sys.puts(data.col1 + " ... " + data.col2);
});
Note reader.setColumnNames()
resets the column names so next invocation of the data
listener will again receive the data in an array rather than an object.
Convert the /etc/passwd
file to comma separated format, drop commented lines and dump the results to the standard output:
var reader = csv.createCsvFileReader('/etc/passwd', {
'separator': ':',
'quote': '"',
'escape': '"',
'comment': '#',
});
var writer = new csv.CsvWriter(process.stdout);
reader.addListener('data', function(data) {
writer.writeRecord(data);
});
Parsing an upload as the data comes in, using node-formidable:
upload_form.onPart = function(part) {
if (!part.filename) { upload_form.handlePart(part); return }
var reader = csv.createCsvFileReader({'comment': '#'});
reader.addListener('data', function(data) {
saveRecord(data);
});
part.on('data', function(buffer) {
// Pipe incoming data into the reader.
reader.parse(buffer);
});
part.on('end', function() {
reader.end()
})
}
CsvReader Options
Note: the defaults are based on the values from RFC 4180 - https://tools.ietf.org/html/rfc4180
separator
- field separator (delimiter), default: ',' (comma)quote
- the character used to enclose fields with white space characters, escaping etc., default: '"' (double quote)escape
- character used to escape thequote
inside a field, default: '"' (double quote). If you are changingquotechar
you may want to change theescape
to the same valuecomment
- parser will ignore this character and all following characters on the same line the line, default: nonecolumnNames
- an array of column names, if used, the rows sent to thedata
listener are represented as hashes instead of arrays, default: nonecolumnsFromHeader
- boolean value indicating whether the first row should be interpreted as a list of header names. If used, the rows sent to thedata
listener are represented as hashes instead of arrays, default:false
nestedQuotes
- boolean value indicating whether the parser should try to process a file with unescaped quote characters inside fields, default:false
flags
- a string with flags to be passed through to createRead/WriteStream (only supported viacreateCsvFileReader
andcreateCsvFileWriter
methods), default: none
CSvWriter Options
separator
- field separator (delimiter), default: ',' (comma)quote
- the character used to enclose fields with white space characters, escaping etc., default: '"' (double quote)escape
- character used to escape thequote
inside a field, default: '"' (double quote). If you are changingquotechar
you may want to change theescape
to the same valueescapeFormulas
- boolean value indicating whether the parser should escape '=', '+' and '-' with an apostrophe to prevent some programs from treating the content as an executable formula, default:false
4 years ago
4 years ago
7 years ago
10 years ago
10 years ago
12 years ago
12 years ago
12 years ago
12 years ago
13 years ago
13 years ago
13 years ago
13 years ago
13 years ago
13 years ago
13 years ago
13 years ago
13 years ago