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This is a Python module to compare version numbers. It's case insensitive
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and recognizes all major notations, prefixes (ver. and version), delimiters
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(. - and _) and suffixes (alpha, beta, rc, preview and trunk).
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Usage: compareVersions(version1, version2)
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The function accepts arguments of any type convertable to unicode string
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and returns integer value:
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0 - the versions are equal
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1 - version 1 is higher
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2 - version 2 is higher
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-----------------------------------------------------------------------------
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First, both arguments are converted to uppercase unicode and stripped of
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'VERSION' or 'VER.' prefix. Then they are chopped into a list of particular
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numeric and alphabetic elements. The dots, dashes and underlines are recognized
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as delimiters. Also numbers and non numbers are separated. See example below:
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'Ver 0.03-120_rc7foo' is converted to ['0','03','120','RC','7','FOO']
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Then every pair of elements, from left to right, is compared as string
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or as number to provide the best result (you know, 11>9 but also '03'>'007').
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The comparing stops when one of elements is greater. If comparing achieves
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the end of the shorter list and the matter is still unresolved, the longer
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list is usually recognized as higher, except following suffixes:
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ALPHA, BETA, RC, PREVIEW and TRUNK which make the version number lower.
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/***************************************************************************
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* Copyright (C) 2008-11-24 Borys Jurgiel *
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***************************************************************************
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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***************************************************************************/
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# ------------------------------------------------------------------------ #
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def normalizeVersion(s):
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""" remove possible prefix from given string and convert to uppercase """
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prefixes = ['VERSION','VER.','VER','V.','V','REVISION','REV.','REV','R.','R']
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s = unicode(s).upper()
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# ------------------------------------------------------------------------ #
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def classifyCharacter(c):
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""" return 0 for delimiter, 1 for digit and 2 for alphabetic character """
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if c in [".","-","_"," "]:
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# ------------------------------------------------------------------------ #
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""" convert string to list of numbers and words """
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for i in range(1,len(s)):
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if classifyCharacter(s[i]) == 0:
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elif classifyCharacter(s[i]) == classifyCharacter(s[i-1]):
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# ------------------------------------------------------------------------ #
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def compareElements(s1,s2):
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""" compare two particular elements """
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# check if the matter is easy solvable:
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# try to compare as numeric values (but only if the first character is not 0):
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if s1 and s2 and s1.isnumeric() and s2.isnumeric() and s1[0] != '0' and s2[0] != '0':
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if float(s1) == float(s2):
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elif float(s1) > float(s2):
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# if the strings aren't numeric or start from 0, compare them as a strings:
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# but first, set ALPHA < BETA < PREVIEW < RC < TRUNK < [NOTHING] < [ANYTHING_ELSE]
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if not s1 in ['ALPHA','BETA','PREVIEW','RC','TRUNK']:
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if not s2 in ['ALPHA','BETA','PREVIEW','RC','TRUNK']:
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# ------------------------------------------------------------------------ #
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def compareVersions(a,b):
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""" Compare two version numbers. Return 0 if a==b or error, 1 if a<b and 2 if b>a """
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a = normalizeVersion(a)
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b = normalizeVersion(b)
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# convert the strings to the lists
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# set the shorter string as a base
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# try to determine within the common length
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if compareElements(v1[i],v2[i]):
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return compareElements(v1[i],v2[i])
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# if the lists are identical till the end of the shorther string, try to compare the odd tail
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#with the simple space (because the 'alpha', 'beta', 'preview' and 'rc' are LESS then nothing)
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return compareElements(v1[l],u' ')
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return compareElements(u' ',v2[l])
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# if everything else fails...