132 lines
4.2 KiB
Python
132 lines
4.2 KiB
Python
# ismn.py - functions for handling ISMNs
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#
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# Copyright (C) 2010, 2011, 2012, 2013 Arthur de Jong
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#
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# This library is free software; you can redistribute it and/or
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# modify it under the terms of the GNU Lesser General Public
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# License as published by the Free Software Foundation; either
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# version 2.1 of the License, or (at your option) any later version.
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#
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# This library is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# Lesser General Public License for more details.
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#
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# You should have received a copy of the GNU Lesser General Public
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# License along with this library; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301 USA
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"""ISMN (International Standard Music Number).
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The ISMN (International Standard Music Number) is used to identify sheet
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music. This module handles both numbers in the 10-digit 13-digit format.
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>>> validate('979-0-3452-4680-5')
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'9790345246805'
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>>> validate('9790060115615')
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'9790060115615'
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>>> ismn_type(' M-2306-7118-7')
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'ISMN10'
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>>> validate('9790060115614')
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Traceback (most recent call last):
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...
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InvalidChecksum: ...
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>>> compact(' 979-0-3452-4680-5')
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'9790345246805'
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>>> format('9790060115615')
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'979-0-060-11561-5'
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>>> format('M230671187')
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'979-0-2306-7118-7'
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>>> to_ismn13('M230671187')
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'9790230671187'
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"""
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from stdnum import ean
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from stdnum.exceptions import *
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from stdnum.util import clean
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def compact(number):
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"""Convert the ISMN to the minimal representation. This strips the number
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of any valid ISMN separators and removes surrounding whitespace."""
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return clean(number, ' -.').strip().upper()
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def validate(number):
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"""Checks to see if the number provided is a valid ISMN (either a legacy
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10-digit one or a 13-digit one). This checks the length and the check
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bit but does not check if the publisher is known."""
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number = compact(number)
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if len(number) == 10:
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if number[0] != 'M':
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raise InvalidFormat()
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ean.validate('9790' + number[1:])
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else:
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ean.validate(number)
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return number
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def ismn_type(number):
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"""Check the type of ISMN number passed and return 'ISMN13', 'ISMN10'
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or None (for invalid)."""
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try:
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number = validate(number)
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except ValidationError:
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return None
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if len(number) == 10:
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return 'ISMN10'
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elif len(number) == 13:
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return 'ISMN13'
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def is_valid(number):
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"""Checks to see if the number provided is a valid ISMN (either a legacy
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10-digit one or a 13-digit one). This checks the length and the check
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bit but does not check if the publisher is known."""
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try:
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return bool(validate(number))
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except ValidationError:
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return False
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def to_ismn13(number):
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"""Convert the number to ISMN13 (EAN) format."""
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number = number.strip()
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min_number = compact(number)
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if len(min_number) == 13:
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return number # nothing to do, already 13 digit format
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# add prefix and strip the M
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if ' ' in number:
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return '979 0' + number[1:]
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elif '-' in number:
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return '979-0' + number[1:]
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else:
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return '9790' + number[1:]
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# these are the ranges allocated to publisher codes
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_ranges = (
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(3, '000', '099'), (4, '1000', '3999'), (5, '40000', '69999'),
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(6, '700000', '899999'), (7, '9000000', '9999999'))
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def split(number):
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"""Split the specified ISMN into a bookland prefix (979), an ISMN
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prefix (0), a publisher element (3 to 7 digits), an item element (2 to
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6 digits) and a check digit."""
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# clean up number
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number = to_ismn13(compact(number))
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# rind the correct range and split the number
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for length, low, high in _ranges:
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if low <= number[4:4 + length] <= high:
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return (number[:3], number[3], number[4:4 + length],
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number[4 + length:-1], number[-1])
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def format(number, separator='-'):
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"""Reformat the passed number to the standard format with the
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prefixes, the publisher element, the item element and the check-digit
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separated by the specified separator. The number is converted to the
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13-digit format silently."""
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return separator.join(x for x in split(number) if x)
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