def systemFromSystem(self, systemElement, systemObj=None):
r'''
returns a :class:`~music21.stream.System` object from a <system> tag.
The System object will contain :class:`~music21.stream.Part` objects
which will have the notes, etc. contained in it.
TODO: Handle multiple <voices>
'''
if systemObj is None:
systemObj = stream.System()
stavesList = self.getChildrenByTag(systemElement, 'staves')
if len(stavesList) == 0:
raise CapellaImportException(
"No <staves> tag found in this <system> element")
elif len(stavesList) > 1:
raise CapellaImportException(
"More than one <staves> tag found in this <system> element")
stavesElement = stavesList[0]
staffList = self.getChildrenByTag(stavesElement, 'staff')
if len(stavesList) == 0:
raise CapellaImportException(
"No <staff> tag found in the <staves> element for this <system> element"
)
for thisStaffElement in staffList:
# do something with defaultTime
partId = "UnknownPart"
if 'layout' in thisStaffElement._attrs:
partId = thisStaffElement._attrs['layout'].value
partObj = stream.Part()
partObj.id = partId
voicesList = self.getChildrenByTag(thisStaffElement, 'voices')
if len(voicesList) == 0:
raise CapellaImportException(
"No <voices> tag found in the <staff> tag for the <staves> element for this <system> element"
)
voicesElement = voicesList[0]
voiceList = self.getChildrenByTag(voicesElement, 'voice')
if len(voiceList) == 0:
raise CapellaImportException(
"No <voice> tag found in the <voices> tag for the <staff> tag for the <staves> element for this <system> element"
)
if len(voiceList) == 1: # single voice staff... perfect!
thisVoiceElement = voiceList[0]
noteObjectsList = self.getChildrenByTag(
thisVoiceElement, 'noteObjects')
if len(noteObjectsList) == 0:
raise CapellaImportException(
"No <noteObjects> tag found in the <voice> tag found in the <voices> tag for the <staff> tag for the <staves> element for this <system> element"
)
elif len(noteObjectsList) > 1:
raise CapellaImportException(
"More than one <noteObjects> tag found in the <voice> tag found in the <voices> tag for the <staff> tag for the <staves> element for this <system> element"
)
thisNoteObject = noteObjectsList[0]
self.streamFromNoteObjects(thisNoteObject, partObj)
systemObj.insert(0, partObj)
return systemObj
def systemFromSystem(self, systemElement, systemObj=None):
r'''
returns a :class:`~music21.stream.System` object from a <system> tag.
The System object will contain :class:`~music21.stream.Part` objects
which will have the notes, etc. contained in it.
TODO: Handle multiple <voices>
'''
if systemObj is None:
systemObj = stream.System()
stavesList = systemElement.findall('staves')
if not stavesList:
raise CapellaImportException('No <staves> tag found in this <system> element')
if len(stavesList) > 1:
raise CapellaImportException(
'More than one <staves> tag found in this <system> element')
stavesElement = stavesList[0]
staffList = stavesElement.findall('staff')
if not stavesList:
raise CapellaImportException(
'No <staff> tag found in the <staves> element for this <system> element')
for thisStaffElement in staffList:
# do something with defaultTime
partId = 'UnknownPart'
if 'layout' in thisStaffElement.attrib:
partId = thisStaffElement.attrib['layout']
partObj = stream.Part()
partObj.id = partId
voicesList = thisStaffElement.findall('voices')
if not voicesList:
raise CapellaImportException(
'No <voices> tag found in the <staff> tag for the <staves> element '
+ 'for this <system> element')
voicesElement = voicesList[0]
voiceList = voicesElement.findall('voice')
if not voiceList:
raise CapellaImportException(
'No <voice> tag found in the <voices> tag for the <staff> tag for the '
+ '<staves> element for this <system> element')
if len(voiceList) == 1: # single voice staff... perfect!
thisVoiceElement = voiceList[0]
noteObjectsList = thisVoiceElement.findall('noteObjects')
if not noteObjectsList:
raise CapellaImportException(
'No <noteObjects> tag found in the <voice> tag found in the '
+ '<voices> tag for the <staff> tag for the <staves> element for '
+ 'this <system> element')
if len(noteObjectsList) > 1:
raise CapellaImportException(
'More than one <noteObjects> tag found in the <voice> tag found '
+ 'in the <voices> tag for the <staff> tag for the <staves> element '
+ 'for this <system> element')
thisNoteObject = noteObjectsList[0]
self.streamFromNoteObjects(thisNoteObject, partObj)
systemObj.insert(0, partObj)
return systemObj