Merge pull request #1631 from TimFelixBeyer/pythonic-for-loops

Simplify code and speed up for loops

music21/analysis/patel.py

@@ -10,7 +10,7 @@
 # ------------------------------------------------------------------------------
 from __future__ import annotations
 
-import math
+from statistics import mean, stdev
 import unittest
 
 def nPVI(streamForAnalysis):
@@ -98,15 +98,7 @@ def melodicIntervalVariability(streamForAnalysis, **skipKeywords):
                              + 'a std-deviation of intervals (and thus a MIV)')
     # summation = 0
     semitoneList = [myInt.chromatic.undirected for myInt in intervalStream]
-    mean = 0
-    std = 0
-    for a in semitoneList:
-        mean = mean + a
-    mean = mean / totalElements
-    for a in semitoneList:
-        std = std + (a - mean) ** 2
-    std = math.sqrt(std / (totalElements - 1))
-    return 100 * (std / mean)
+    return 100 * (stdev(semitoneList) / mean(semitoneList))
 
 
 class Test(unittest.TestCase):

music21/base.py

@@ -257,11 +257,9 @@ def __eq__(self, other: object):
 
         if len(self) != len(other):
             return False
-        sls = sorted(self)
-        slo = sorted(other)
 
-        for x in range(len(sls)):
-            if sls[x].lower() != slo[x].lower():
+        for eSelf, eOther in zip(sorted(self), sorted(other)):
+            if eSelf.lower() != eOther.lower():
                 return False
         return True
 
@@ -3267,9 +3265,7 @@ def splitAtQuarterLength(
 
         elif addTies and isinstance(e, chord.Chord) and isinstance(eRemain, chord.Chord):
             # the last isinstance is redundant, but MyPy needs it.
-            for i in range(len(e.notes)):
-                component = e.notes[i]
-                remainComponent = eRemain.notes[i]
+            for component, remainComponent in zip(e.notes, eRemain.notes):
                 forceEndTieType = 'stop'
                 if component.tie is not None:
                     # the last tie of what was formally a start should
@@ -3352,8 +3348,7 @@ def splitByQuarterLengths(
         eList = []
         spannerList = []  # this does not fully work with trills over multiple splits yet.
         eRemain = copy.deepcopy(self)
-        for qlIndex in range(len(quarterLengthList) - 1):
-            qlSplit = quarterLengthList[qlIndex]
+        for qlSplit in quarterLengthList[:-1]:
             st = eRemain.splitAtQuarterLength(qlSplit,
                                               addTies=addTies,
                                               displayTiedAccidentals=displayTiedAccidentals)

music21/beam.py

@@ -334,10 +334,8 @@ def removeSandwichedUnbeamables(beamsList: list[Beams | None]):
                 beamNext = beamsList[i + 1]
             else:
                 beamNext = None
-
             if beamLast is None and beamNext is None:
                 beamsList[i] = None
-
             beamLast = beamsList[i]
 
         return beamsList
@@ -350,9 +348,7 @@ def mergeConnectingPartialBeams(beamsList):
         16ths are not beamed by default.
         '''
         # sanitize two partials in a row:
-        for i in range(len(beamsList) - 1):
-            bThis = beamsList[i]
-            bNext = beamsList[i + 1]
+        for i, (bThis, bNext) in enumerate(zip(beamsList[:-1], beamsList[1:])):
             if not bThis or not bNext:
                 continue
 
@@ -387,9 +383,7 @@ def mergeConnectingPartialBeams(beamsList):
                 nextBeam.direction = None
 
         # now fix partial-lefts that follow stops:
-        for i in range(1, len(beamsList)):
-            bThis = beamsList[i]
-            bPrev = beamsList[i - 1]
+        for bThis, bPrev in zip(beamsList[1:], beamsList[:-1]):
             if not bThis or not bPrev:
                 continue
 
@@ -416,17 +410,17 @@ def mergeConnectingPartialBeams(beamsList):
         return beamsList
 
     @staticmethod
-    def sanitizePartialBeams(beamsList):
+    def sanitizePartialBeams(beamsList: list[Beams | None]) -> list[Beams | None]:
         '''
         It is possible at a late stage to have beams that only consist of partials
         or beams with a 'start' followed by 'partial/left' or possibly 'stop' followed
         by 'partial/right'; beams entirely consisting of partials are removed
         and the direction of irrational partials is fixed.
         '''
-        for i in range(len(beamsList)):
-            if beamsList[i] is None:
+        for i, beamsObj in enumerate(beamsList):
+            if beamsObj is None:
                 continue
-            allTypes = beamsList[i].getTypes()
+            allTypes = beamsObj.getTypes()
             # clear elements that have partial beams with no full beams:
             if 'start' not in allTypes and 'stop' not in allTypes and 'continue' not in allTypes:
                 # nothing but partials
@@ -436,7 +430,8 @@ def sanitizePartialBeams(beamsList):
             # follow a stop
             hasStart = False
             hasStop = False
-            for b in beamsList[i].beamsList:
+            b: Beam
+            for b in beamsObj.beamsList:
                 if b.type == 'start':
                     hasStart = True
                     continue
@@ -583,9 +578,9 @@ def getByNumber(self, number):
         '''
         if number not in self.getNumbers():
             raise IndexError(f'beam number {number} cannot be accessed')
-        for i in range(len(self)):
-            if self.beamsList[i].number == number:
-                return self.beamsList[i]
+        for beam in self.beamsList:
+            if beam.number == number:
+                return beam
 
     def getNumbers(self):
         '''
@@ -695,10 +690,10 @@ def setByNumber(self, number, type, direction=None):  # type is okay @ReservedAs
             raise BeamException(f'beam type cannot be {type}')
         if number not in self.getNumbers():
             raise IndexError(f'beam number {number} cannot be accessed')
-        for i in range(len(self)):
-            if self.beamsList[i].number == number:
-                self.beamsList[i].type = type
-                self.beamsList[i].direction = direction
+        for beam in self.beamsList:
+            if beam.number == number:
+                beam.type = type
+                beam.direction = direction
 
 
 # -----------------------------------------------------------------------------

music21/duration.py

@@ -862,15 +862,11 @@ def ordinal(self):
         >>> c.ordinal
         14
         '''
-        ordinalFound = None
-        for i in range(len(ordinalTypeFromNum)):
-            if self.type == ordinalTypeFromNum[i]:
-                ordinalFound = i
-                break
-        if ordinalFound is None:
+        try:
+            return ordinalTypeFromNum.index(self.type)
+        except ValueError:
             raise DurationException(
-                f'Could not determine durationNumber from {ordinalFound}')
-        return ordinalFound
+                f'Could not determine durationNumber from {self.type}')
 
 
 _durationTupleCacheTypeDots: dict[tuple[str, int], DurationTuple] = {}
@@ -2135,18 +2131,14 @@ def componentIndexAtQtrPosition(self, quarterPosition):
             return self.components[-1]
 
         currentPosition = 0.0
-        indexFound = None
-        for i in range(len(self.components)):
-            currentPosition = opFrac(currentPosition + self.components[i].quarterLength)
+        for i, component in enumerate(self.components):
+            currentPosition = opFrac(currentPosition + component.quarterLength)
             if currentPosition > quarterPosition:
-                indexFound = i
-                break
-        if indexFound is None:
-            raise DurationException(
-                'Could not match quarter length within an index.')
-        return indexFound
+                return i
+        raise DurationException(
+            'Could not match quarterLength within an index.')
 
-    def componentStartTime(self, componentIndex):
+    def componentStartTime(self, componentIndex: int) -> float:
         '''
         For a valid component index value, this returns the quarter note offset
         at which that component would start.
@@ -2172,15 +2164,13 @@ def componentStartTime(self, componentIndex):
         IndexError: invalid component index value 3 submitted;
                     value must be an integer between 0 and 2
         '''
-        if componentIndex not in range(len(self.components)):
+        if not (0 <= componentIndex < len(self.components)):
             raise IndexError(
                 f'invalid component index value {componentIndex} '
                 + f'submitted; value must be an integer between 0 and {len(self.components) - 1}')
+        components = self.components[:componentIndex]
+        return float(sum([c.quarterLength for c in components]))
 
-        currentPosition = 0.0
-        for i in range(componentIndex):
-            currentPosition += self.components[i].quarterLength
-        return currentPosition
 
     def consolidate(self):
         '''
@@ -2624,10 +2614,10 @@ def dotGroups(self, value: tuple[int, ...]):
         if not isinstance(value, tuple):
             raise TypeError('only tuple dotGroups values can be used with this method.')
         # removes dots from all components...
-        components = list(self._components)
-        for i in range(len(self._components)):
-            components[i] = durationTupleFromTypeDots(self._components[i].type, 0)
-        self._components = tuple(components)
+        componentsGenerator = (
+            durationTupleFromTypeDots(component.type, 0) for component in self._components
+        )
+        self._components = tuple(componentsGenerator)
 
         self._dotGroups = value
         self._quarterLengthNeedsUpdating = True

music21/interval.py

@@ -2560,23 +2560,24 @@ def _stringToDiatonicChromatic(
         dirScale = -1
     else:
         dirScale = 1
+    value_lower = value.lower()
 
-    if 'descending' in value.lower():
+    if 'descending' in value_lower:
         value = re.sub(r'descending\s*', '', value, flags=re.RegexFlag.IGNORECASE)
         dirScale = -1
-    elif 'ascending' in value.lower():
+    elif 'ascending' in value_lower:
         value = re.sub(r'ascending\\s*', '', value, flags=re.RegexFlag.IGNORECASE)
 
     # permit whole and half abbreviations
-    if value.lower() in ('w', 'whole', 'tone'):
+    if value_lower in ('w', 'whole', 'tone'):
         value = 'M2'
         inferred = True
-    elif value.lower() in ('h', 'half', 'semitone'):
+    elif value_lower in ('h', 'half', 'semitone'):
         value = 'm2'
         inferred = True
 
     for i, ordinal in enumerate(common.musicOrdinals):
-        if ordinal.lower() in value.lower():
+        if ordinal.lower() in value_lower:
             value = re.sub(fr'\s*{ordinal}\s*',
                            str(i),
                            value,

music21/metadata/__init__.py

@@ -1138,7 +1138,7 @@ def search(
 
                     # environLocal.printDebug(['comparing fields:', f, field])
                     # look for partial match in all fields
-                    if field.lower() in uniqueName.lower():
+                    if field in uniqueName.lower():
                         valueFieldPairs.append((value, uniqueName))
                         match = True
                         break
@@ -1149,21 +1149,20 @@ def search(
                         uniqueName, None
                     )
 
-                    if not workId:
+                    if workId is None:
                         # there is no associated grandfathered workId, don't search it
                         continue
 
                     # look for partial match in all fields
-                    if field.lower() in workId.lower():
+                    if field in workId.lower():
                         valueFieldPairs.append((value, workId))
                         match = True
                         break
         else:  # get all fields
             for uniqueName, value in self.all(skipContributors=True):
-                if not self._isStandardUniqueName(uniqueName):
-                    # custom metadata, don't search it
-                    continue
-                valueFieldPairs.append((value, uniqueName))
+                # only search standard metadata
+                if self._isStandardUniqueName(uniqueName):
+                    valueFieldPairs.append((value, uniqueName))
 
         # now get all (or field-matched) contributor names, using contrib.role
         # as field name, so clients can search by custom contributor role.
@@ -1970,13 +1969,7 @@ def _isStandardUniqueName(self, uniqueName: str) -> bool:
         False
 
         '''
-        prop: PropertyDescription | None = (
-            properties.UNIQUE_NAME_TO_PROPERTY_DESCRIPTION.get(uniqueName, None)
-        )
-        if prop is None:
-            return False
-
-        return True
+        return uniqueName in properties.UNIQUE_NAME_TO_PROPERTY_DESCRIPTION
 
     @staticmethod
     def _isStandardNamespaceName(namespaceName: str) -> bool:

music21/metadata/caching.py

@@ -356,12 +356,11 @@ def process_parallel(jobs, processCount=None):
         # end generator
 
     @staticmethod
-    def process_serial(jobs):
+    def process_serial(jobs: list[MetadataCachingJob]):
         '''
         Process jobs serially.
         '''
         remainingJobs = len(jobs)
-        results = []
         for job in jobs:
             results, errors = job.run()
             remainingJobs -= 1

music21/metadata/primitives.py

@@ -862,10 +862,10 @@ def __init__(self,
     def __str__(self):
         if isinstance(self._data, bytes):
             return self._data.decode('UTF-8')
-        elif not isinstance(self._data, str):
-            return str(self._data)
-        else:
+        elif isinstance(self._data, str):
             return self._data
+        else:
+            return str(self._data)
 
     def _reprInternal(self):
         return str(self)