view abcrange.py @ 608:b4eb1753c80f

Up the resolution of the web graphics. This will result in increased image size, on the order of 18k->32k, but I'm fed up with the blurriness of the current images. Ideally I'd move to SVG for the web images, but Mick reckons that SVG support on mobile browsers is still limited. Suspect he's probably right.
author Jim Hague <jim.hague@acm.org>
date Fri, 04 Nov 2016 23:31:40 +0000
parents 1b79867b4f35
children 2f6e05d0aba0
line wrap: on
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#!/usr/bin/env python3
#
# Find the range of a tune. Do minimal parsing of an ABC input file
# and print the lowest and highest notes therein. Accidentals are
# ignored.
#
# The output is given in purely numeric form, to avoid needing to
# re-parse it in an external script. A single line is printed with
# the highest note followed by a space and the lowest note. Middle C ('C') is
# 100. D an octave about ('d') is 108. D an octave above that ('d'') is
# 205. D below middle C ('d,') is 94. And so on.
#
# For example:
# $./abcrange.py choon.abc
# choon.abc: 112 97
#

import sys

def process(filename, inf):
    highest = 0
    lowest = 1000
    for line in inf:
        line = line.strip()
        # If it is empty or starts "%", ignore it.
        if len(line) == 0 or line[0] == "%":
            continue

        # Is it a header line? I.e. does it start LETTER COLON?
        # If so, ignore.
        start = line[:2]
        if len(start) > 1 and start[1] == ":" and (start[0].isalpha() or start[0] == '+'):
            continue

        # Tune line.
        inchord = False
        note = 0
        notevals = {
            "C": 100,
            "D": 101,
            "E": 102,
            "F": 103,
            "G": 104,
            "A": 105,
            "B": 106,
            "c": 107,
            "d": 108,
            "e": 109,
            "f": 110,
            "g": 111,
            "a": 112,
            "b": 113,
        }
        for c in line:
            if c == "," and note > 0:
                note = note - 7
                continue
            elif c == "'" and note > 0:
                note = note + 7
                continue

            if note > 0:
                if note > highest:
                    highest = note
                if note < lowest:
                    lowest = note
                note = 0

            if c == '"':
                inchord = not inchord
                continue
            if inchord:
                continue

            if c in notevals:
                note = notevals[c]

        if note > 0:
            if note > highest:
                highest = note
            if note < lowest:
                lowest = note
            note = 0

    print("{0}: {1} {2}".format(filename, highest, lowest))

if len(sys.argv) > 1:
    for arg in sys.argv[1:]:
        try:
            inf = open(arg, "r")
            process(arg, inf)
        finally:
            inf.close()
else:
    process("stdin", sys.stdin)