import re
from .databasehandler import DatabaseHandler
from .objects.chartdata import ChartData
from .objects.songdata import SongData
from .objects.artistdata import ArtistData
[docs]class ChartParser:
"""
Parses data from a chord chart. Looks for information like title, key, chords, and structure.
"""
sectionKeywords = ["intro", "verse", "prechorus", "pre-chorus", "pre chorus", "chorus", "bridge", "outro", "solo", "hook", "pre-hook", "coda", "middle 8", "interlude"]
chordSymbols = ["m", "M", "min", "maj", "dim"] # TRIADS
chordSymbols.extend(["m7", "M7", "min7", "maj7", "dim7", "m7b5"]) # SEVENTHS
chordSymbols.extend(["aug", "+", "7#5", "M7+5", "M7+", "m7+", "7+"]) # AUGMENTED
chordSymbols.extend(["sus2", "sus4", "7sus4", "11", "sus4b9", "susb9"]) # SUSPENDED
chordSymbols.extend(["6", "m6", "M6", "maj6", "6/7", "67", "6/9", "69"]) # SIXTHS
chordSymbols.extend(["9", "add9", "m9", "maj9", "M9", "7b9", "7#9"]) # NINTHS
chordSymbols.extend(["11", "add11", "7#11", "m11"]) # ELEVENTHS
chordSymbols.extend(["13", "add13", "M13", "m13", "maj13"]) # THIRTEENTHS
chordSymbols.extend(["7b9", "7#9", "67", "6/7", "add2", "5"]) # ALTERATIONS
def __init__(self):
self.dbHandler = DatabaseHandler()
self.artistData = None
self._resetSongData()
def _resetSongData(self):
self.chordList = []
self.sectionList = []
[docs] def _isChordSymbol(self, text):
"""
Returns true if the given text is a chord symbol.
"""
# We can't use word boundaries (/b) since # is not a word character!
regexRoot = r"[CDEFGAB](#{1,2}|b{1,2})?"
regexChords = r"("
for idx, chordSymbol in enumerate(ChartParser.chordSymbols):
if idx != 0:
regexChords += r"|"
regexChords += re.escape(chordSymbol)
regexChords += r")"
finalPattern = re.compile(regexRoot + regexChords + r"?(\/" + regexRoot + r")?")
return finalPattern.fullmatch(text)
[docs] def _removeSlashChordBass(self, chordSymbol):
"""
Remove the bass note from slash chord symbols. For example, this function would take "Gm7/Bb" and return "Gm7".
"""
rePattern = re.compile(r"\/[CDEFGAB](#{1,2}|b{1,2})?$")
return rePattern.sub("", chordSymbol)
[docs] def _isSectionSymbol(self, text):
"""
Returns true if the given text is probably a section marking, such as "Chorus" or "Verse".
"""
regexSections = r"[ \[\{]*("
for idx, sectionKeyword in enumerate(ChartParser.sectionKeywords):
if idx != 0:
regexSections += r"|"
regexSections += re.escape(sectionKeyword)
regexSections += r")[ 1-9:]*[ \]\}]*"
finalPattern = re.compile(regexSections, re.IGNORECASE)
return finalPattern.fullmatch(text)
[docs] def _parseChords(self, chartText):
"""
Parses the chord chart for chord symbols, such as "Gmaj7" or "F#m7b5"
"""
chords = []
tokens = chartText.split()
for token in tokens:
if self._isChordSymbol(token):
formattedToken = self._removeSlashChordBass(token)
if len(chords) == 0:
# if the chords list is empty, add the chordSymbol
chords.append(formattedToken)
else:
if formattedToken != chords[-1]:
# add the chord symbol only if it's different from the previous one.
chords.append(formattedToken)
return chords
[docs] def _parseSections(self, textLine):
"""
Parses the chord chart for section markings, such as "Chorus" or "Verse".
"""
sections = []
keywordExists = False
keywordToken = None
tokens = textLine.split()
for token in tokens:
if self._isSectionSymbol(token):
keywordExists = True
keywordToken = token
if keywordExists:
formmatedKeyword = keywordToken.upper()
formmatedKeyword = formmatedKeyword.replace("[", "")
formmatedKeyword = formmatedKeyword.replace("]", "")
formmatedKeyword = formmatedKeyword.replace(":", "")
formmatedKeyword = formmatedKeyword.replace(" ", "")
sections.append(formmatedKeyword)
return sections
[docs] def _checkIfChartIsDefinitive(self, currentChartData, otherCharts):
"""
Checks multiple charts for this song to determine the "definitive" version.
Returns true if the current chart is more detailed, meaning it has more sections OR has more chord symbols
"""
isDefinitive = 0
if len(otherCharts) > 0:
for otherChartData in otherCharts:
if (len(currentChartData.chordsSpecific) > len(otherChartData.chordsSpecific)
or len(currentChartData.sections) > len(otherChartData.sections)):
# currentChartData is more detailed, and is more definitive!
isDefinitive = 1
else:
# If there are no other charts, this one is the definitive!
isDefinitive = 1
return isDefinitive
[docs] def parseChart(self, songTitle, chartSourceUrl, chartContent):
"""
Core function of the Parser.
Calls a series of internal parsing methods to extract data from a chord chart.
"""
chartData = ChartData()
lines = chartContent.splitlines()
chartData.artist = self.artistData.name # TODO - check if this is still needed
chartData.title = songTitle.upper() # TODO - check if this is still needed
chartData.source = chartSourceUrl
for line in lines:
self.chordList.extend(self._parseChords(line))
self.sectionList.extend(self._parseSections(line))
chartData.chordsSpecific = self.chordList
chartData.sections = self.sectionList
self._resetSongData()
print("Parsed data for " + chartData.title)
newSongData = SongData()
newSongData.title = chartData.title
self.dbHandler.saveSongData(self.artistData, newSongData)
# Check other charts for this song.
# If this chart is more detailed (has more sections and has more chord symbols),
# This current chart becomes the "definitive" chart for that song.
otherCharts = self.dbHandler.getChartsForSong(self.artistData, newSongData)
isDefinitiveChart = self._checkIfChartIsDefinitive(chartData, otherCharts)
self.dbHandler.saveChartData(self.artistData, newSongData, chartData, isDefinitiveChart)
[docs] def setArtistData(self, name, sources, artistSourceUrls):
"""
Sets the current artist info for the parser.
"""
freshArtistData = ArtistData()
freshArtistData.name = name.upper()
freshArtistData.sourceNames = sources
freshArtistData.sourceUrls = artistSourceUrls
self.artistData = freshArtistData
print("Saving artist data to database...")
self.dbHandler.saveArtistData(self.artistData)