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music21.converter

music21.converter contains tools for loading music from various file formats, whether from disk, from the web, or from text, into music21.stream.:class:~music21.stream.Score objects (or other similar stream objects).

The most powerful and easy to use tool is the parse() function. Simply provide a filename, URL, or text string and, if the format is supported, a Score will be returned.

This is the most general public interface for all formats. Programmers adding their own formats to the system should provide an interface here to their own parsers (such as humdrum, musicxml, etc.)

The second and subsequent times that a file is loaded it will likely be much faster since we store a parsed version of each file as a “pickle” object in the temp folder on the disk.

>>> from music21 import *
>>> s = converter.parse('d:/mydocs/schubert.krn')
>>> s
<music21.stream.Score ...>
music21.converter.parse(value, *args, **keywords)

Given a file path, encoded data in a Python string, or a URL, attempt to parse the item into a Stream. Note: URL downloading will not happen automatically unless the user has set their Environment “autoDownload” preference to “allow”.

Keywords can include number which specifies a piece number in a file of multipiece file.

format specifies the format to parse the line of text or the file as.

A string of text is first checked to see if it is a filename that exists on disk. If not it is searched to see if it looks like a URL. If not it is processed as data.

The data is normally interpreted as a line of TinyNotation with the first argument being the time signature:

TODO: SHOW FILE TODO: SHOW URL

>>> from music21 import *
>>> s = converter.parse("tinyNotation: 3/4 E4 r f# g=lastG trip{b-8 a g} c")
>>> s.getElementsByClass(meter.TimeSignature)[0]
<music21.meter.TimeSignature 3/4>

>>> s2 = converter.parse("E8 f# g#' G f g# g G#", "2/4")
>>> s2.show('text')
{0.0} <music21.meter.TimeSignature 2/4>
{0.0} <music21.note.Note E>
{0.5} <music21.note.Note F#>
{1.0} <music21.note.Note G#>
{1.5} <music21.note.Note G>
{2.0} <music21.note.Note F>
{2.5} <music21.note.Note G#>
{3.0} <music21.note.Note G>
{3.5} <music21.note.Note G#>
music21.converter.parseFile(fp, number=None, format=None, forceSource=False)

Given a file path, attempt to parse the file into a Stream.

music21.converter.parseData(dataStr, number=None, format=None)

Given musical data represented within a Python string, attempt to parse the data into a Stream.

music21.converter.parseURL(url, number=None, format=None, forceSource=False)

Given a URL, attempt to download and parse the file into a Stream. Note: URL downloading will not happen automatically unless the user has set their Environment “autoDownload” preference to “allow”.

music21.converter.freeze(streamObj, fmt=None, fp=None)

Given a StreamObject and a file path, serialize and store the Stream to a file.

This function is based on the StreamFreezer object.

The serialization format is defined by the fmt argument; ‘pickle’ (the default), ‘jsonpickle’ or ‘jsonnative’ are presently supported.

If no file path is given, a temporary file is used.

The file path is returned.

>>> from music21 import *
>>> c = converter.parse('c4 d e f', '4/4')
>>> c.show('text')
{0.0} <music21.meter.TimeSignature 4/4>
{0.0} <music21.note.Note C>
{1.0} <music21.note.Note D>
{2.0} <music21.note.Note E>
{3.0} <music21.note.Note F>
>>> fp = converter.freeze(c, fmt='pickle')
>>> fp
'/tmp/music21/sjiwoe.p'

The file can then be “defrosted” back into a Stream using the unfreeze() method.

>>> d = converter.unfreeze(fp)
>>> d.show('text')
{0.0} <music21.meter.TimeSignature 4/4>
{0.0} <music21.note.Note C>
{1.0} <music21.note.Note D>
{2.0} <music21.note.Note E>
{3.0} <music21.note.Note F>
music21.converter.unfreeze(fp)

Given a file path of a serialized Stream, defrost the file into a Stream.

This function is based on the StreamFreezer object.

See the documentation for freeze() for demos.

music21.converter.freezeStr(streamObj, fmt=None)

Given a StreamObject and a file path, serialize and return a serialization string.

This function is based on the StreamFreezer object.

The serialization format is defined by the fmt argument; ‘pickle’ (the default), ‘jsonpickle’ or ‘jsonnative’ are presently supported.

>>> from music21 import *
>>> c = converter.parse('c4 d e f', '4/4')
>>> c.show('text')
{0.0} <music21.meter.TimeSignature 4/4>
{0.0} <music21.note.Note C>
{1.0} <music21.note.Note D>
{2.0} <music21.note.Note E>
{3.0} <music21.note.Note F>
>>> data = converter.freezeStr(c, fmt='pickle')
>>> len(data) > 20 # pickle implementation dependent
True
>>> d = converter.unfreezeStr(data)
>>> d.show('text')
{0.0} <music21.meter.TimeSignature 4/4>
{0.0} <music21.note.Note C>
{1.0} <music21.note.Note D>
{2.0} <music21.note.Note E>
{3.0} <music21.note.Note F>
music21.converter.unfreezeStr(strData)

Given a serialization string, defrost into a Stream.

This function is based on the StreamFreezer object.

Converter

class music21.converter.Converter

A class used for converting all supported data formats into music21 objects.

Not a subclass, but a wrapper for different converter objects based on format.

Converter attributes

Attributes without Documentation: validHeaderFormats

Converter properties

stream

All converters have to have a stream property or attribute.

Converter methods

formatFromHeader(dataStr)

if dataStr begins with a text header such as “tinyNotation:” then return that format plus the dataStr with the head removed.

Else, return (None, dataStr) where dataStr is the original untouched.

Not case sensitive.

>>> from music21 import *
>>> c = converter.Converter()
>>> c.formatFromHeader('tinynotation: C4 E2')
('tinyNotation', 'C4 E2')

>>> c.formatFromHeader('C4 E2')
(None, 'C4 E2')
parseData(dataStr, number=None, format=None, forceSource=False)

Given raw data, determine format and parse into a music21 Stream.

parseFile(fp, number=None, format=None, forceSource=False)

Given a file path, parse and store a music21 Stream.

If format is None then look up the format from the file extension using common.findFormatFile.

parseURL(url, format=None, number=None)

Given a url, download and parse the file into a music21 Stream stored in the stream property of the converter object.

Note that this checks the user Environment autoDownlaad setting before downloading.

As a convenience method, links to Wikifonia main page for a piece are redirected to the musicxml (n.b., it is up to you to determine if any piece on Wikifonia is in or out of copyright in your juristiction).

Demonstration of rewrite ability for URLs. Actual URL is http://static.wikifonia.org/4391/musicxml.xml but the URL below is what’s shown on the browser, so either is accepted.

>>> from music21 import *
>>> jeanieLightBrownURL = 'http://www.wikifonia.org/node/4391'
>>> c = converter.Converter()
>>> c.parseURL(jeanieLightBrownURL)
>>> jeanieStream = c.stream

ConverterMusicXML

class music21.converter.ConverterMusicXML(forceSource)

Converter for MusicXML

ConverterMusicXML properties

stream

No documentation.

ConverterMusicXML methods

getPartNames()

No documentation.

load()

Load all parts from a MusicXML object representation. This determines the order parts are found in the stream

parseData(xmlString, number=None)

Open MusicXML data from a string.

parseFile(fp, number=None)

Open from a file path; check to see if there is a pickled version available and up to date; if so, open that, otherwise open source.

ConverterHumdrum

class music21.converter.ConverterHumdrum

Simple class wrapper for parsing Humdrum data provided in a file or in a string.

ConverterHumdrum attributes

Attributes without Documentation: stream

ConverterHumdrum methods

parseData(humdrumString, number=None)

Open Humdrum data from a string

>>> humdata = '**kern\n*M2/4\n=1\n24r\n24g#\n24f#\n24e\n24c#\n24f\n24r\n24dn\n24e-\n24gn\n24e-\n24dn\n*-'
>>> c = ConverterHumdrum()
>>> s = c.parseData(humdata)
parseFile(filepath, number=None)

Open Humdram data from a file path.

ArchiveManager

class music21.converter.ArchiveManager(fp, archiveType='zip')

Before opening a file path, this class can check if this is an archived file collection, such as a .zip or or .mxl file. This will return the data from the archive.

Only archive type supported now is zip.

ArchiveManager methods

getData(name=None, format='musicxml')

Return data from the archive by name. If no name is given, a default may be available.

For ‘musedata’ format this will be a list of strings. For ‘musicxml’ this will be a single string.

getNames()

Return a list of all names contained in this archive.

isArchive()

Return True or False if the filepath is an archive of the supplied archiveType.

ConverterABC

class music21.converter.ConverterABC

Simple class wrapper for parsing ABC.

ConverterABC properties

stream

No documentation.

ConverterABC methods

parseData(strData, number=None)

Get ABC data, as token list, from a string representation. If more than one work is defined in the ABC data, a Opus object will be returned; otherwise, a Score is returned.

parseFile(fp, number=None)

Get MIDI data from a file path. If more than one work is defined in the ABC data, a Opus object will be returned; otherwise, a Score is returned.

If number is provided, and this ABC file defines multiple works with a X: tag, just the specified work will be returned.

ConverterMidi

class music21.converter.ConverterMidi

Simple class wrapper for parsing MIDI.

ConverterMidi properties

stream

No documentation.

ConverterMidi methods

parseData(strData, number=None)

Get MIDI data from a binary string representation.

parseFile(fp, number=None)

Get MIDI data from a file path.

ConverterMuseData

class music21.converter.ConverterMuseData

Simple class wrapper for parsing MuseData.

ConverterMuseData properties

stream

No documentation.

ConverterMuseData methods

parseData(strData, number=None)

Get musedata from a string representation.

parseFile(fp, number=None)

ConverterNoteworthy

class music21.converter.ConverterNoteworthy

Simple class wrapper for parsing NoteworthyComposer data provided in a file or in a string.

Gets data with the file format .nwctxt

Users should not need this routine. The basic format is

>>> from music21 import *
>>> paertPath = converter.parse('d:/desktop/arvo_part_o_weisheit.nwctxt')
>>> paertStream = converter.parse(paertPath)
>>> len(paertStream.parts)
4

For developers: see the documentation for parseData() and parseFile() to see the low-level usage.

ConverterNoteworthy attributes

Attributes without Documentation: stream

ConverterNoteworthy methods

parseData(nwcData)

Open Noteworthy data from a string or list

>>> nwcData = "!NoteWorthyComposer(2.0)\n|AddStaff\n|Clef|Type:Treble\n|Note|Dur:Whole|Pos:1^"
>>> c = ConverterNoteworthy()
>>> c.parseData(nwcData)
>>> c.stream.show('text')
{0.0} <music21.stream.Part ...>
    {0.0} <music21.stream.Measure 0 offset=0.0>
        {0.0} <music21.clef.TrebleClef>
        {0.0} <music21.note.Note C>
parseFile(fp, number=None)

Open Noteworthy data (as nwctxt) from a file path.

>>> from music21 import *
>>> paertPath = converter.parse('d:/desktop/arvo_part_o_weisheit.nwctxt')
>>> c = ConverterNoteworthy()
>>> c.parseFile(filePath)
>>> c.stream.show()

ConverterRomanText

class music21.converter.ConverterRomanText

Simple class wrapper for parsing roman text harmonic definitions.

ConverterRomanText properties

stream

No documentation.

ConverterRomanText methods

parseData(strData, number=None)
parseFile(fp, number=None)

ConverterTinyNotation

class music21.converter.ConverterTinyNotation

Simple class wrapper for parsing TinyNotation data provided in a file or in a string.

ConverterTinyNotation attributes

Attributes without Documentation: stream

ConverterTinyNotation methods

parseData(tnData, number=None)

Open TinyNotation data from a string or list

>>> tnData = ["E4 r f# g=lastG trip{b-8 a g} c", "3/4"]
>>> c = ConverterTinyNotation()
>>> s = c.parseData(tnData)
parseFile(fp, number=None)

Open TinyNotation data from a file path.

PickleFilter

class music21.converter.PickleFilter(fp, forceSource=False)

Before opening a file path, this class can check if there is an up to date version pickled and stored in the scratch directory.

If the user has not specified a scratch directory, a pickle path will not be created.

Provide a file path to check if there is pickled version.

If forceSource is True, pickled files, if available, will not be returned.

PickleFilter methods

status()

Given a file path specified with __init__, look for an up to date pickled version of this file path. If it exists, return its fp, other wise return the original file path.

Return arguments are file path to load, boolean whether to write a pickle, and the file path of the pickle.

StreamFreezer

class music21.converter.StreamFreezer(streamObj=None)

This class is used to freeze a Stream, preparing it for serialization and providing conversion routines.

In general, use the freeze() and unfreeze() functions for serializing to a file. Use the unfreeze()

>>> from music21 import *
>>> s = stream.Stream()
>>> s.repeatAppend(note.Note('C4'), 8)
>>> temp = [s[n].transpose(n, inPlace=True) for n in range(len(s))]

>>> sf = StreamFreezer(s) # provide a Stream at init
>>> data = sf.writeStr(fmt='pickle') # pickle is default format; jsonpickle
>>> sfOut = StreamFreezer()
>>> sfOut.openStr(data)
>>> s = sfOut.stream
>>> s.show('t')
{0.0} <music21.note.Note C>
{1.0} <music21.note.Note D->
{2.0} <music21.note.Note D>
{3.0} <music21.note.Note E->
{4.0} <music21.note.Note E>
{5.0} <music21.note.Note F>
{6.0} <music21.note.Note G->
{7.0} <music21.note.Note G>

StreamFreezer attributes

Attributes without Documentation: stream

StreamFreezer methods

open(fp)

For a supplied file path to a pickled stream, unpickle

openStr(fileData)

Open a String as a pickle

write(fmt=None, fp=None)

For a supplied Stream, write a serialized version.

writeStr(fmt=None)

Return a pickled as String