def addStaffTags(measure: Element,
staffNumber: int,
tagList: Optional[List[str]] = None):
'''
For a <measure> tag `measure`, add a <staff> grandchild to any instance of
a child tag of a type in `tagList`.
>>> from xml.etree.ElementTree import fromstring as El
>>> from music21.musicxml.partStaffExporter import addStaffTags
>>> from music21.musicxml.helpers import dump
>>> elem = El("""
... <measure number="1">
... <note>
... <rest measure="yes" />
... <duration>8</duration>
... </note>
... </measure>"""
... )
>>> addStaffTags(elem, 2, tagList=['note', 'forward', 'direction', 'harmony'])
>>> dump(elem)
<measure number="1">
<note>
<rest measure="yes" />
<duration>8</duration>
<staff>2</staff>
</note>
</measure>
Raise if a <staff> grandchild is already present:
>>> addStaffTags(elem, 2, tagList=['note', 'forward', 'direction'])
Traceback (most recent call last):
music21.musicxml.xmlObjects.MusicXMLExportException:
In part (), measure (1): Attempted to create a second <staff> tag
The function doesn't accept elements other than <measure>:
>>> addStaffTags(elem.find('note'), 2, tagList=['direction'])
Traceback (most recent call last):
music21.musicxml.xmlObjects.MusicXMLExportException:
addStaffTags() only accepts <measure> tags
'''
if measure.tag != 'measure':
raise MusicXMLExportException(
'addStaffTags() only accepts <measure> tags')
for tagName in tagList:
for tag in measure.findall(tagName):
if tag.find('staff') is not None:
e = MusicXMLExportException(
'Attempted to create a second <staff> tag')
e.measureNumber = measure.get('number')
raise e
mxStaff = Element('staff')
mxStaff.text = str(staffNumber)
helpers.insertBeforeElements(
tag,
mxStaff,
tagList=['beam', 'notations', 'lyric', 'play', 'sound'])
def getRootForPartStaff(self, partStaff: stream.PartStaff) -> Element:
'''
Look up the <part> Element being used to represent the music21 `partStaff`.
>>> from music21.musicxml import testPrimitive
>>> s = converter.parse(testPrimitive.pianoStaff43a)
>>> SX = musicxml.m21ToXml.ScoreExporter(s)
>>> SX.scorePreliminaries()
>>> SX.parsePartlikeScore()
>>> SX.getRootForPartStaff(s.parts[0])
<Element 'part' at 0x...
>>> other = stream.PartStaff()
>>> other.id = 'unrelated'
>>> SX.getRootForPartStaff(other)
Traceback (most recent call last):
music21.musicxml.xmlObjects.MusicXMLExportException:
<music21.stream.PartStaff unrelated> not found in self.partExporterList
'''
for pex in self.partExporterList:
if partStaff is pex.stream:
return pex.xmlRoot
# now try derivations:
for pex in self.partExporterList:
for derived in pex.stream.derivation.chain():
if derived is partStaff:
return pex.xmlRoot
# now just match on id:
for pex in self.partExporterList:
if partStaff.id == pex.stream.id:
return pex.xmlRoot
for pex in self.partExporterList:
for derived in pex.stream.derivation.chain():
if partStaff.id == derived.id:
return pex.xmlRoot
raise MusicXMLExportException(
f'{partStaff} not found in self.partExporterList')
def moveMeasureContents(measure: Element, otherMeasure: Element,
staffNumber: int):
# noinspection PyShadowingNames
'''
Move the child elements of `measure` into `otherMeasure`;
create voice numbers if needed;
bump voice numbers if they conflict;
account for <backup> and <forward> tags;
skip <print> tags;
set "number" on midmeasure clef changes;
replace existing <barline> tags.
>>> from xml.etree.ElementTree import fromstring as El
>>> measure = El('<measure><note /></measure>')
>>> otherMeasure = El('<measure><note /></measure>')
>>> SX = musicxml.m21ToXml.ScoreExporter
>>> SX.moveMeasureContents(measure, otherMeasure, 2)
>>> SX().dump(otherMeasure)
<measure>
<note>
<voice>1</voice>
</note>
<note>
<voice>2</voice>
</note>
</measure>
>>> SX.moveMeasureContents(El('<junk />'), otherMeasure, 2)
Traceback (most recent call last):
music21.musicxml.xmlObjects.MusicXMLExportException:
moveMeasureContents() called on <Element 'junk'...
Only one <barline> should be exported per merged measure:
>>> from music21.musicxml import testPrimitive
>>> s = converter.parse(testPrimitive.mixedVoices1a)
>>> SX = musicxml.m21ToXml.ScoreExporter(s)
>>> root = SX.parse()
>>> root.findall('part/measure/barline')
[<Element 'barline' at 0x...]
'''
if measure.tag != 'measure' or otherMeasure.tag != 'measure':
raise MusicXMLExportException(
f'moveMeasureContents() called on {measure} and {otherMeasure} (not measures).'
)
maxVoices: int = 0
otherMeasureLackedVoice: bool = False
for voice in otherMeasure.findall('*/voice'):
maxVoices = max(maxVoices, int(voice.text))
if maxVoices == 0:
otherMeasureLackedVoice = True
for elem in otherMeasure.findall('note'):
voice = Element('voice')
voice.text = '1'
helpers.insertBeforeElements(elem,
voice,
tagList=[
'type',
'dot',
'accidental',
'time-modification',
'stem',
'notehead',
'notehead-text',
'staff',
])
maxVoices = 1
# Create <backup>
amountToBackup: int = 0
for dur in otherMeasure.findall('note/duration'):
amountToBackup += int(dur.text)
for dur in otherMeasure.findall('forward/duration'):
amountToBackup += int(dur.text)
for backupDur in otherMeasure.findall('backup/duration'):
amountToBackup -= int(backupDur.text)
if amountToBackup:
mxBackup = Element('backup')
mxDuration = SubElement(mxBackup, 'duration')
mxDuration.text = str(amountToBackup)
otherMeasure.append(mxBackup)
# Move elements
for elem in measure.findall('*'):
# Skip elements that already exist in otherMeasure
if elem.tag == 'print':
continue
if elem.tag == 'attributes':
if elem.findall('divisions'):
# This is likely the initial mxAttributes
continue
for midMeasureClef in elem.findall('clef'):
midMeasureClef.set('number', str(staffNumber))
if elem.tag == 'barline':
# Remove existing <barline>, if any
for existingBarline in otherMeasure.findall('barline'):
otherMeasure.remove(existingBarline)
if elem.tag == 'note':
voice = elem.find('voice')
if voice is not None:
if otherMeasureLackedVoice:
# otherMeasure assigned voice 1; Bump voice number here
voice.text = str(int(voice.text) + 1)
else:
pass # No need to alter existing voice numbers
else:
voice = Element('voice')
voice.text = str(maxVoices + 1)
helpers.insertBeforeElements(elem,
voice,
tagList=[
'type', 'dot',
'accidental',
'time-modification',
'stem', 'notehead',
'notehead-text', 'staff'
])
# Append to otherMeasure
otherMeasure.append(elem)
def setEarliestAttributesAndClefsPartStaff(self, group: StaffGroup):
'''
Set the <staff>, <key>, <time>, and <clef> information on the earliest
measure <attributes> tag in the <part> representing the joined PartStaffs.
Need the earliest <attributes> tag, which may not exist in the merged <part>
until moved there by movePartStaffMeasureContents() --
e.g. RH of piano doesn't appear until m. 40, and earlier music for LH needs
to be merged first in order to find earliest <attributes>.
Called by :meth:`joinPartStaffs`
Multiple keys:
>>> from music21.musicxml import testPrimitive
>>> xmlDir = common.getSourceFilePath() / 'musicxml' / 'lilypondTestSuite'
>>> s = converter.parse(xmlDir / '43b-MultiStaff-DifferentKeys.xml')
>>> SX = musicxml.m21ToXml.ScoreExporter(s)
>>> root = SX.parse()
>>> m1 = root.find('part/measure')
>>> SX.dump(m1)
<measure number="1">
<attributes>
<divisions>10080</divisions>
<key number="1">
<fifths>0</fifths>
</key>
<key number="2">
<fifths>2</fifths>
</key>
<time>
<beats>4</beats>
<beat-type>4</beat-type>
</time>
<staves>2</staves>
<clef number="1">
<sign>G</sign>
<line>2</line>
</clef>
<clef number="2">
<sign>F</sign>
<line>4</line>
</clef>
</attributes>
...
</measure>
Multiple meters (not very well supported by MusicXML readers):
>>> from music21.musicxml import testPrimitive
>>> s = converter.parse(testPrimitive.pianoStaffPolymeter)
>>> SX = musicxml.m21ToXml.ScoreExporter(s)
>>> root = SX.parse()
>>> m1 = root.find('part/measure')
>>> SX.dump(m1)
<measure number="1">
<attributes>
<divisions>10080</divisions>
<key>
<fifths>0</fifths>
</key>
<time number="1">
<beats>4</beats>
<beat-type>4</beat-type>
</time>
<time number="2">
<beats>2</beats>
<beat-type>2</beat-type>
</time>
<staves>2</staves>
<clef number="1">
<sign>G</sign>
<line>2</line>
</clef>
<clef number="2">
<sign>F</sign>
<line>4</line>
</clef>
</attributes>
...
</measure>
'''
def isMultiAttribute(m21Class, comparison: str = '__eq__') -> bool:
'''
Return True if any first instance of m21Class in any subsequent staff
in this StaffGroup does not compare to the first instance of that class
in the earliest staff where found (not necessarily the first) using `comparison`.
'''
initialM21Instance: Optional[m21Class] = None
for ps in group:
if initialM21Instance is None:
initialM21Instance = ps.recurse().getElementsByClass(
m21Class).first()
else:
firstInstanceSubsequentStaff = ps.recurse(
).getElementsByClass(m21Class).first()
if firstInstanceSubsequentStaff is not None:
comparisonWrapper = getattr(
firstInstanceSubsequentStaff, comparison)
if not comparisonWrapper(initialM21Instance):
return True
# else, keep looking: 3+ staves
# else, keep looking: 3+ staves
return False
multiKey: bool = isMultiAttribute(KeySignature)
multiMeter: bool = isMultiAttribute(TimeSignature,
comparison='ratioEqual')
initialPartStaffRoot: Optional[Element] = None
mxAttributes: Optional[Element] = None
for i, ps in enumerate(group):
staffNumber: int = i + 1 # 1-indexed
# Initial PartStaff in group: find earliest mxAttributes, set clef #1 and <staves>
if initialPartStaffRoot is None:
initialPartStaffRoot = self.getRootForPartStaff(ps)
mxAttributes: Element = initialPartStaffRoot.find(
'measure/attributes')
clef1: Optional[Element] = mxAttributes.find('clef')
if clef1 is not None:
clef1.set('number', '1')
mxStaves = Element('staves')
mxStaves.text = str(len(group))
helpers.insertBeforeElements(mxAttributes,
mxStaves,
tagList=[
'part-symbol', 'instruments',
'clef', 'staff-details',
'transpose', 'directive',
'measure-style'
])
if multiKey:
key1 = mxAttributes.find('key')
if key1:
key1.set('number', '1')
if multiMeter:
meter1 = mxAttributes.find('time')
if meter1:
meter1.set('number', '1')
# Subsequent PartStaffs in group: set additional clefs on mxAttributes
else:
thisPartStaffRoot: Element = self.getRootForPartStaff(ps)
oldClef: Optional[Element] = thisPartStaffRoot.find(
'measure/attributes/clef')
if oldClef is not None and mxAttributes is not None:
clefsInMxAttributesAlready = mxAttributes.findall('clef')
if len(clefsInMxAttributesAlready) >= staffNumber:
e = MusicXMLExportException(
'Attempted to add more clefs than staffs')
e.partName = ps.partName
raise e
# Set initial clef for this staff
newClef = Element('clef')
newClef.set('number', str(staffNumber))
newSign = SubElement(newClef, 'sign')
newSign.text = oldClef.find('sign').text
newLine = SubElement(newClef, 'line')
newLine.text = oldClef.find('line').text
helpers.insertBeforeElements(mxAttributes,
newClef,
tagList=[
'staff-details',
'transpose', 'directive',
'measure-style'
])
if multiMeter:
oldMeter: Optional[Element] = thisPartStaffRoot.find(
'measure/attributes/time')
if oldMeter:
oldMeter.set('number', str(staffNumber))
helpers.insertBeforeElements(mxAttributes,
oldMeter,
tagList=['staves'])
if multiKey:
oldKey: Optional[Element] = thisPartStaffRoot.find(
'measure/attributes/key')
if oldKey:
oldKey.set('number', str(staffNumber))
helpers.insertBeforeElements(
mxAttributes, oldKey, tagList=['time', 'staves'])
def processSubsequentPartStaff(self, target: Element, source: Element,
staffNum: int) -> Dict:
'''
Move elements from subsequent PartStaff's measures into `target`: the <part>
element representing the initial PartStaff that will soon represent the merged whole.
Called by
:meth:`movePartStaffMeasureContents`,
which is in turn called by
:meth:`joinPartStaffs`.
'''
DIVIDER_COMMENT = '========================= Measure [NNN] =========================='
PLACEHOLDER = '[NNN]'
sourceMeasures = iter(source.findall('measure'))
sourceMeasure = None # Set back to None when disposed of
insertions = {}
# Walk through <measures> of the target <part>, compare measure numbers
for i, targetMeasure in enumerate(target):
if targetMeasure.tag != 'measure':
continue
if sourceMeasure is None:
try:
sourceMeasure = next(sourceMeasures)
except StopIteration:
return insertions # done processing this PartStaff
targetNumber = targetMeasure.get('number')
sourceNumber = sourceMeasure.get('number')
# 99% of the time we expect identical sets of measure numbers
# So walking through each should yield the same numbers, whether ints or strings
if targetNumber == sourceNumber:
# No gaps found: move all contents
self.moveMeasureContents(sourceMeasure, targetMeasure,
staffNum)
sourceMeasure = None
continue
# Or, gap in measure numbers in the subsequent part: keep iterating through target
if helpers.measureNumberComesBefore(targetNumber, sourceNumber):
continue # sourceMeasure is not None!
# Or, gap in measure numbers in target: record necessary insertions until gap is closed
while helpers.measureNumberComesBefore(sourceNumber, targetNumber):
divider: Element = ET.Comment(
DIVIDER_COMMENT.replace(PLACEHOLDER, sourceNumber))
try:
insertions[i] += [divider, sourceMeasure]
except KeyError:
insertions[i] = [divider, sourceMeasure]
try:
sourceMeasure = next(sourceMeasures)
except StopIteration:
return insertions
raise MusicXMLExportException(
'joinPartStaffs() was unable to order the measures '
f'{targetNumber}, {sourceNumber}') # pragma: no cover
# Exhaust sourceMeasure and sourceMeasures
remainingMeasures = list(sourceMeasures)
if sourceMeasure is not None:
remainingMeasures.insert(0, sourceMeasure)
for remaining in remainingMeasures:
sourceNumber = remaining.get('number')
divider: Element = ET.Comment(
DIVIDER_COMMENT.replace(PLACEHOLDER, sourceNumber))
try:
insertions[len(target)] += [divider, remaining]
except KeyError:
insertions[len(target)] = [divider, remaining]
return insertions
def setEarliestAttributesAndClefsPartStaff(self, group: StaffGroup):
'''
Set the <staff> and <clef> information on the earliest measure <attributes> tag
in the <part> representing the joined PartStaffs.
Need the earliest <attributes> tag, which may not exist in the merged <part>
until moved there by movePartStaffMeasureContents() --
e.g. RH of piano doesn't appear until m. 40, and earlier music for LH needs
to be merged first in order to find earliest <attributes>.
Called by :meth:`~music21.musicxml.partStaffExporter.PartStaffExporterMixin.joinPartStaffs`
>>> from music21.musicxml import testPrimitive
>>> s = converter.parse(testPrimitive.pianoStaff43a)
>>> SX = musicxml.m21ToXml.ScoreExporter(s)
>>> root = SX.parse()
>>> m1 = root.find('part/measure')
>>> SX.dump(m1)
<measure number="1">
<attributes>
<divisions>10080</divisions>
<key>
<fifths>0</fifths>
</key>
<time>
<beats>4</beats>
<beat-type>4</beat-type>
</time>
<staves>2</staves>
<clef number="1">
<sign>G</sign>
<line>2</line>
</clef>
<clef number="2">
<sign>F</sign>
<line>4</line>
</clef>
</attributes>
...
</measure>
'''
initialPartStaffRoot: Optional[Element] = None
mxAttributes: Optional[Element] = None
for i, ps in enumerate(group):
staffNumber: int = i + 1 # 1-indexed
# Initial PartStaff in group: find earliest mxAttributes, set clef #1 and <staves>
if initialPartStaffRoot is None:
initialPartStaffRoot = self.getRootForPartStaff(ps)
mxAttributes: Element = initialPartStaffRoot.find(
'measure/attributes')
clef1: Optional[Element] = mxAttributes.find('clef')
if clef1 is not None:
clef1.set('number', '1')
mxStaves = Element('staves')
mxStaves.text = str(len(group))
helpers.insertBeforeElements(mxAttributes,
mxStaves,
tagList=[
'part-symbol', 'instruments',
'clef', 'staff-details',
'transpose', 'directive',
'measure-style'
])
# Subsequent PartStaffs in group: set additional clefs on mxAttributes
else:
thisPartStaffRoot: Element = self.getRootForPartStaff(ps)
oldClef: Optional[Element] = thisPartStaffRoot.find(
'measure/attributes/clef')
if oldClef is not None and mxAttributes is not None:
clefsInMxAttributesAlready = mxAttributes.findall('clef')
if len(clefsInMxAttributesAlready) >= staffNumber:
raise MusicXMLExportException(
'Attempted to add more clefs than staffs'
) # pragma: no cover
# Set initial clef for this staff
newClef = Element('clef')
newClef.set('number', str(staffNumber))
newSign = SubElement(newClef, 'sign')
newSign.text = oldClef.find('sign').text
newLine = SubElement(newClef, 'line')
newLine.text = oldClef.find('line').text
helpers.insertBeforeElements(mxAttributes,
newClef,
tagList=[
'staff-details',
'transpose', 'directive',
'measure-style'
])
