1# grid.py - functions for handling Global Release Identifier (GRid) numbers 2# 3# Copyright (C) 2010, 2011, 2012, 2013 Arthur de Jong 4# 5# This library is free software; you can redistribute it and/or 6# modify it under the terms of the GNU Lesser General Public 7# License as published by the Free Software Foundation; either 8# version 2.1 of the License, or (at your option) any later version. 9# 10# This library is distributed in the hope that it will be useful, 11# but WITHOUT ANY WARRANTY; without even the implied warranty of 12# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13# Lesser General Public License for more details. 14# 15# You should have received a copy of the GNU Lesser General Public 16# License along with this library; if not, write to the Free Software 17# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 18# 02110-1301 USA 19 20"""GRid (Global Release Identifier). 21 22The Global Release Identifier is used to identify releases of digital 23sound recordings and uses the ISO 7064 Mod 37, 36 algorithm to verify the 24correctness of the number. 25 26>>> validate('A12425GABC1234002M') 27'A12425GABC1234002M' 28>>> validate('Grid: A1-2425G-ABC1234002-M') 29'A12425GABC1234002M' 30>>> validate('A1-2425G-ABC1234002-Q') # incorrect check digit 31Traceback (most recent call last): 32 ... 33InvalidChecksum: ... 34>>> compact('A1-2425G-ABC1234002-M') 35'A12425GABC1234002M' 36>>> format('A12425GABC1234002M') 37'A1-2425G-ABC1234002-M' 38""" 39 40from stdnum.exceptions import * 41from stdnum.util import clean 42 43 44def compact(number): 45 """Convert the GRid to the minimal representation. This strips the 46 number of any valid separators and removes surrounding whitespace.""" 47 number = clean(number, ' -').strip().upper() 48 if number.startswith('GRID:'): 49 number = number[5:] 50 return number 51 52 53def validate(number): 54 """Check if the number is a valid GRid.""" 55 from stdnum.iso7064 import mod_37_36 56 number = compact(number) 57 if len(number) != 18: 58 raise InvalidLength() 59 return mod_37_36.validate(number) 60 61 62def is_valid(number): 63 """Check if the number is a valid GRid.""" 64 try: 65 return bool(validate(number)) 66 except ValidationError: 67 return False 68 69 70def format(number, separator='-'): 71 """Reformat the number to the standard presentation format.""" 72 number = compact(number) 73 number = (number[0:2], number[2:7], number[7:17], number[17:]) 74 return separator.join(x for x in number if x) 75