我是编程和Python的新手,但我目前的很多研究都是关注从musicxml文件中提取数据。我有一段音乐,想要提取不属于关键签名一部分的意外事件。我不知道怎么做,请有人帮忙吗?以下是我正在查看的musicxml文件中的一个度量示例:
<measure number='19'>
<print new-system='no'/>
<note>
<rest/>
<duration>768</duration>
<voice>1</voice>
<type>quarter</type>
<staff>1</staff>
</note>
<backup>
<duration>768</duration>
</backup>
<note>
<pitch>
<step>E</step>
<octave>4</octave>
</pitch>
<duration>2304</duration>
<tie type='start'/>
<voice>2</voice>
<type>half</type>
<dot/>
<staff>1</staff>
<notations>
<tied type='start'/>
<slur type='stop' number='1'/>
</notations>
</note>
<backup>
<duration>1536</duration>
</backup>
<note>
<pitch>
<step>E</step>
<alter>3</alter>
<octave>3</octave>
</pitch>
<duration>1536</duration>
<voice>1</voice>
<type>half</type>
<staff>1</staff>
</note>
<note>
<chord/>
<pitch>
<step>G</step>
<alter>4</alter>
<octave>3</octave>
</pitch>
<duration>1536</duration>
<voice>1</voice>
<type>half</type>
<staff>1</staff>
</note>
<backup>
<duration>2304</duration>
</backup>
<note>
<pitch>
<step>E</step>
<octave>2</octave>
</pitch>
<duration>2304</duration>
<voice>5</voice>
<type>half</type>
<dot/>
<staff>2</staff>
</note>
</measure>
问题转化为搜索musicxml文件并计算次数
<pitch>
<step>*</step>
<alter>**</alter>
...
在*不是(F或C)的情况下发生,并且还发现*为F或C且未跟<alter>
标记的次数。
非常感谢任何帮助或建议!
答案 0 :(得分:5)
我无法提供Python详细信息,但我有两个与MusicXML相关的建议:
1)你的问题是用偶然事件来表达的,但是你的代码关注的是alter元素。 alter元素用于音高变换;意外因素是用于书面意外的。你在找哪一个?在MusicXML中,声音的多少以及它在符号中的显示方式之间的二重性很常见,对于使用MusicXML文件进行研究非常重要。
2)如果您不熟悉编程和Python,我建议使用专为音乐学设计的高级工具包,并提供良好的MusicXML支持。您将把问题域移到更高的级别,这可以让您更快地取得进展。对此的明显选择是music21工具包,它也是用Python编写的。在http://web.mit.edu/music21/处有更多信息。
祝你的研究好运!
答案 1 :(得分:3)
python有一个xml.dom模块,允许您快速浏览xml文件。如果您有任何Web开发经验,它与javascript的文档对象模型非常相似。
from xml.dom.minidom import parse, parseString
def get_step(note):
stepNode = note.getElementsByTagName("step")[0]
#get the text from the Text Node within the <step>,
#and convert it from unicode to ascii
return str(stepNode.childNodes[0].nodeValue)
def get_alter(note):
alters = note.getElementsByTagName("alter")
if len(alters) == 0:
return None
return alters[0]
def is_rest(note):
return len(note.getElementsByTagName("rest")) > 0
def is_accidental(note):
return get_alter(note) != None
dom = parse("data.xml")
notes = dom.getElementsByTagName("note")
#rests don't have steps or alters, so we don't care about them. Filter them out.
notes = filter(lambda note: not is_rest(note), notes)
#compile a list of notes of all accidentals (notes with <alter> tags)
accidentals = filter(is_accidental, notes)
#remove notes that are F or C
accidentals_that_are_not_f_or_c = filter(lambda note: get_step(note) not in ["F", "C"], accidentals)
#compile a list of notes that don't contain the alter tag
non_accidentals = filter(lambda note: not is_accidental(note), notes)
#remove notes that are not F or C
non_accidentals_that_are_f_or_c = filter(lambda note: get_step(note) in ["F", "C"], non_accidentals)
print "Accidental notes that are not F or C:"
if len(accidentals_that_are_not_f_or_c) == 0:
print "(None found)"
else:
for note in accidentals_that_are_not_f_or_c:
print get_step(note)
print "Non-accidental notes that are F or C:"
if len(non_accidentals_that_are_f_or_c) == 0:
print "(None found)"
else:
for note in non_accidentals_that_are_f_or_c:
print get_step(note), get_step(note) in ["F", "C"]
输出:
Accidental notes that are not F or C:
E
G
Non-accidental notes that are F or C:
(None found)