Fix mypy 1.16 issues

Improve typing for music21 based on issues uncovered in mypy 1.16.

Fix error in `Interval.noteEnd = None` -- setting noteStart, noteEnd, pitchStart, or pitchEnd to None raised exceptions

Author: mscuthbert

music21/analysis/discrete.py

@@ -153,7 +153,7 @@ def getSolutionsUsed(self):
                 post.append(solution)
         return post
 
-    def solutionLegend(self, compress=False):
+    def solutionLegend(self, compress: bool = False) -> list[list[str|list[tuple[int|str, str|None]]]]:
         '''
         A list of pairs showing all discrete results and the assigned color.
         Data should be organized to be passed to
@@ -162,7 +162,7 @@ def solutionLegend(self, compress=False):
         If `compress` is True, the legend will only show values for solutions
         that have been encountered.
         '''
-        pass
+        return []
 
     def solutionUnitString(self):
         '''
@@ -211,7 +211,7 @@ class KeyWeightKeyAnalysis(DiscreteAnalysis):
     # favor eb minor
     # C- major cannot be determined if no enharmonics are present
     # C# major can be determined w/o enharmonics
-    keysValidMajor = (
+    keysValidMajor: tuple[str, ...] = (
         'C', 'C#', 'C-',
         'D-', 'D',
         'E-', 'E',
@@ -221,7 +221,7 @@ class KeyWeightKeyAnalysis(DiscreteAnalysis):
         'B-', 'B',
     )
 
-    keysValidMinor = (
+    keysValidMinor: tuple[str, ...] = (
         'C', 'C#',
         'D', 'D#',
         'E-', 'E',
@@ -442,7 +442,7 @@ def _getDifference(self, keyResults, pcDistribution, weightType) -> None|list[fl
                     solution[i] = float(top[i] / ((bottomRight[i] * bottomLeft[i]) ** 0.5))
         return solution
 
-    def solutionLegend(self, compress=False):
+    def solutionLegend(self, compress: bool = False) -> list[list[str|list[tuple[int|str, str|None]]]]:
         '''
         Returns a list of lists of possible results for the creation of a legend.
 
@@ -478,16 +478,18 @@ def solutionLegend(self, compress=False):
             keySortOrderFiltered = _keySortOrder
 
         data = []
-        valid = None
+        valid: tuple[str, ...] = ()
 
+        yLabel: str
         for yLabel in ['Major', 'Minor']:
             if yLabel == 'Major':
                 valid = self.keysValidMajor
             elif yLabel == 'Minor':
                 valid = self.keysValidMinor
 
-            row: list[t.Any] = [yLabel]
-            pairs = []
+            row: list[str|list[tuple[int|str, str|None]]] = [yLabel]
+            pairs: list[tuple[int|str, str|None]] = []
+            color: str|None
             for keyPitch in [pitch.Pitch(p) for p in keySortOrderFiltered]:
                 try:
                     color = self.solutionToColor([keyPitch, yLabel])
@@ -499,6 +501,7 @@ def solutionLegend(self, compress=False):
                         mask = True
                 if keyPitch.name not in valid:
                     mask = True
+
                 if mask:
                     # set as white to maintain spacing
                     color = '#ffffff'
@@ -1076,7 +1079,7 @@ def getPitchSpan(self, subStream) -> tuple[pitch.Pitch, pitch.Pitch]|None:
 
         return minPitchObj, maxPitchObj
 
-    def solutionLegend(self, compress=False):
+    def solutionLegend(self, compress: bool = False) -> list[list[str|list[tuple[int|str, str|None]]]]:
         '''
         Return legend data.
 
@@ -1119,7 +1122,7 @@ def solutionLegend(self, compress=False):
 
         data = []
 
-        colors = {}  # a filtered dictionary
+        colors: dict[int, str] = {}  # a filtered dictionary
         for i in range(len(self._pitchSpanColors.keys())):
             if compress:
                 if self._pitchSpanColors[i] not in colorsUsed:
@@ -1135,8 +1138,8 @@ def solutionLegend(self, compress=False):
 
         # split keys into two groups for two rows (optional)
         for keyGroup in [keysTopRow, keysBottomRow]:
-            row: list[t.Any] = ['']  # empty row label
-            pairs = []
+            row: list[str|list[tuple[int|str, str|None]]] = ['']  # empty row label
+            pairs: list[tuple[int|str, str|None]] = []
             for i in keyGroup:
                 color = colors[i]  # get form colors
                 pairs.append((i, color))
@@ -1151,7 +1154,7 @@ def solutionUnitString(self):
         '''
         return 'Half-Steps'
 
-    def solutionToColor(self, solution):
+    def solutionToColor(self, solution: int|None) -> str:
         '''
 
         >>> p = analysis.discrete.Ambitus()

music21/bar.py

@@ -335,7 +335,7 @@ def times(self) -> int|None:
         return self._times
 
     @times.setter
-    def times(self, value: int):
+    def times(self, value: int|None) -> None:
         if value is None:
             self._times = None
         else:

music21/chord/__init__.py

@@ -3230,6 +3230,8 @@ def isItalianAugmentedSixth(self, *, restrictDoublings=False, permitAnyInversion
             root = self.root()
             third = self.third
             fifth = self.fifth
+            if not fifth:
+                return False
 
             # only the tonic (that is, fifth) can be doubled
             for p in self.pitches:
@@ -4955,7 +4957,10 @@ def _isSeventhWithPerfectFifthsAboveRootAndThird(c: Chord) -> bool:
             hypothetical_fifth = c.root().transpose('P5')
             if hypothetical_fifth.name not in c.pitchNames:
                 return False
-            hypothetical_seventh = c.third.transpose('P5')
+            third = c.third
+            if not third:
+                return False
+            hypothetical_seventh = third.transpose('P5')
             if hypothetical_seventh.name not in c.pitchNames:
                 return False
             return True
@@ -5731,7 +5736,7 @@ def pitches(self) -> tuple[pitch.Pitch, ...]:
         return pitches
 
     @pitches.setter
-    def pitches(self, value: Sequence[str|pitch.Pitch|int]):
+    def pitches(self, value: Iterable[pitch.Pitch]) -> None:
         self._notes = []
         self.clearCache()
         # TODO: individual ties are not being retained here

music21/derivation.py

@@ -153,8 +153,8 @@ def __init__(self, client: base.Music21Object|None = None):
         self._client: weakref.ReferenceType|None = None
         self._clientId: int|None = None  # store python-id to optimize w/o unwrapping
         self._method: str|None = None
-        # origin should be stored as a weak ref -- the place where the client was derived from.
-        self._origin = None
+        # origin could be stored as a weak ref -- the place where the client was derived from.
+        self._origin: base.Music21Object|None = None
         self._originId: int|None = None  # store id to optimize w/o unwrapping
 
         # set client; can handle None

music21/interval.py

@@ -3573,7 +3573,7 @@ def reverse(self):
                             chromatic=self.chromatic.reverse())
 
     @property
-    def pitchStart(self):
+    def pitchStart(self) -> pitch.Pitch|None:
         '''
         Get the start pitch or set it a new value.
         Setting this will adjust the value of the end pitch (`pitchEnd`).
@@ -3618,12 +3618,17 @@ def pitchStart(self):
         return self._pitchStart
 
     @pitchStart.setter
-    def pitchStart(self, p: pitch.Pitch):
+    def pitchStart(self, p: pitch.Pitch|None) -> None:
         '''
         Assuming that this interval is defined,
         we can set a new start Pitch (_pitchStart) and
         automatically set the end Pitch (_pitchEnd).
         '''
+        if p is None:
+            self._pitchStart = None
+            self._pitchEnd = None
+            return
+
         # this is based on the procedure found in transposePitch() and
         # transposeNote() but offers a more object-oriented approach
         pitch2 = self.transposePitch(p)
@@ -3632,7 +3637,7 @@ def pitchStart(self, p: pitch.Pitch):
         self._pitchEnd = pitch2
 
     @property
-    def pitchEnd(self):
+    def pitchEnd(self) -> pitch.Pitch|None:
         '''
         Set the
         end pitch to a new value; this will adjust
@@ -3665,11 +3670,16 @@ def pitchEnd(self):
         return self._pitchEnd
 
     @pitchEnd.setter
-    def pitchEnd(self, p: music21.pitch.Pitch):
+    def pitchEnd(self, p: music21.pitch.Pitch|None) -> None:
         '''
         Assuming that this interval is defined, we can
         set a new end note (_pitchEnd) and automatically have the start pitch (_pitchStart).
         '''
+        if p is None:
+            self._pitchStart = None
+            self._pitchEnd = None
+            return
+
         # this is based on the procedure found in transposePitch() but offers
         # a more object-oriented approach
         pitch1 = self.transposePitch(p, reverse=True)
@@ -3689,9 +3699,11 @@ def noteStart(self) -> music21.note.Note|None:
         elif p:
             from music21 import note
             return note.Note(pitch=p)
+        else:
+            return None
 
     @noteStart.setter
-    def noteStart(self, n: music21.note.Note|None):
+    def noteStart(self, n: music21.note.Note|None) -> None:
         if n:
             self.pitchStart = n.pitch
         else:
@@ -3709,9 +3721,11 @@ def noteEnd(self) -> music21.note.Note|None:
         elif p:
             from music21 import note
             return note.Note(pitch=p)
+        else:
+            return None
 
     @noteEnd.setter
-    def noteEnd(self, n: music21.note.Note|None):
+    def noteEnd(self, n: music21.note.Note|None) -> None:
         if n:
             self.pitchEnd = n.pitch
         else:

music21/musicxml/partStaffExporter.py

@@ -389,7 +389,7 @@ def processSubsequentPartStaff(self,
         DIVIDER_COMMENT = '========================= Measure [NNN] =========================='
         PLACEHOLDER = '[NNN]'
 
-        def makeDivider(inner_sourceNumber: int|str) -> Element:
+        def makeDivider(inner_sourceNumber: int|str) -> Element[t.Any]:
             return Comment(DIVIDER_COMMENT.replace(PLACEHOLDER, str(inner_sourceNumber)))
 
         sourceMeasures = iter(source.findall('measure'))

music21/musicxml/xmlToM21.py

@@ -1779,7 +1779,7 @@ def parseMeasures(self):
         self.removeFinaleIncorrectEndingForwardRest()
         part.coreElementsChanged()
 
-    def removeFinaleIncorrectEndingForwardRest(self):
+    def removeFinaleIncorrectEndingForwardRest(self) -> None:
         '''
         If Finale generated the file AND it ended with an incomplete
         measure (like 4/4 beginning with a quarter pickup and ending
@@ -1793,18 +1793,18 @@ def removeFinaleIncorrectEndingForwardRest(self):
 
         * New in v7.
         '''
-        if self.lastMeasureParser is None:  # pragma: no cover
-            return  # should not happen
         lmp = self.lastMeasureParser
+        if lmp is None:  # pragma: no cover
+            return  # should not happen
         self.lastMeasureParser = None  # clean memory
 
         if lmp.lastForwardTagCreatedByFinale is None:
             return
-        if lmp.useVoices is True:
+        if lmp.useVoices:
             return
         endingForwardRest: note.Rest|None = lmp.lastForwardTagCreatedByFinale
         # important that we find that the last GeneralNote is this Forward tag
-        if lmp.stream[note.GeneralNote].last() is endingForwardRest:
+        if lmp.stream[note.GeneralNote].last() is endingForwardRest and endingForwardRest is not None:
             lmp.stream.remove(endingForwardRest, recurse=True)
 
     def separateOutPartStaves(self) -> list[stream.PartStaff]:
@@ -2379,7 +2379,7 @@ def __init__(self,
         self.staffReference: StaffReferenceType = {}
         self.activeTuplets: list[duration.Tuplet|None] = self.parent.activeTuplets
 
-        self.useVoices = False
+        self.useVoices: bool = False
         self.voicesById: dict[str|int, stream.Voice] = {}
         self.voiceIndices: set[str|int] = set()
         self.staves = 1
@@ -2598,7 +2598,7 @@ def parse(self):
                     meth = getattr(self, methName)
                     meth(mxObj)
 
-        if self.useVoices is True:
+        if self.useVoices:
             for v in self.stream.iter().voices:
                 if v:  # do not bother with empty voices
                     # the musicDataMethods use insertCore, thus the voices need to run

music21/note.py

@@ -881,7 +881,7 @@ def pitches(self) -> tuple[Pitch, ...]:
         return ()
 
     @pitches.setter
-    def pitches(self, _value: Iterable[Pitch]):
+    def pitches(self, _value: Iterable[Pitch]) -> None:
         pass
 
 
@@ -1709,7 +1709,7 @@ def pitches(self) -> tuple[Pitch, ...]:
         return (self.pitch,)
 
     @pitches.setter
-    def pitches(self, value: Sequence[Pitch]):
+    def pitches(self, value: Iterable[Pitch]) -> None:
         if common.isListLike(value) and value:
             self.pitch = value[0]
         else:

music21/percussion.py

@@ -155,7 +155,7 @@ def pitches(self) -> tuple[pitch.Pitch, ...]:
         return pitches
 
     @pitches.setter
-    def pitches(self, value: t.Sequence[str|pitch.Pitch|int]):
+    def pitches(self, value: t.Iterable[pitch.Pitch]) -> None:
         self._notes = []
         # TODO: individual ties are not being retained here
         for p in value:

music21/roman.py

@@ -1209,9 +1209,15 @@ def romanNumeralFromChord(
         rnString = aug6NoKeyObjectSubs[rnString]
         nationalityStart = rnString[:2]  # nb: Ger = Ge
         if nationalityStart in ('It', 'Ge'):
-            keyObj = _getKeyFromCache(chordObj.fifth.name.lower())
+            fifth = chordObj.fifth
+            if t.TYPE_CHECKING:
+                assert fifth is not None
+            keyObj = _getKeyFromCache(fifth.name.lower())
         elif nationalityStart in ('Fr', 'Sw'):
-            keyObj = _getKeyFromCache(chordObj.seventh.name.lower())
+            seventh = chordObj.seventh
+            if t.TYPE_CHECKING:
+                assert seventh is not None
+            keyObj = _getKeyFromCache(seventh.name.lower())
 
     if (
         preferSecondaryDominants