#! /usr/bin/python3 import os import re import sys _defaults = None _old_versions = None _unsupported_versions = None _supported_versions = ["python%s" % ver.strip() for ver in os.environ.get('DEBPYTHON3_SUPPORTED', '').split(',') if ver.strip()] #_default_version = "python%s" % os.environ.get('DEBPYTHON3_DEFAULT', '') #if _default_version == 'python': # _default_version = None _default_version = None def read_default(name=None): global _defaults from configparser import ConfigParser, NoOptionError if not _defaults: if os.path.exists('/usr/share/python3/debian_defaults'): config = ConfigParser() defaultsfile = open('/usr/share/python3/debian_defaults') config.read_file(defaultsfile) defaultsfile.close() _defaults = config if _defaults and name: try: value = _defaults.get('DEFAULT', name) except NoOptionError: raise ValueError return value return None def parse_versions(vstring): if len(vstring.split(',')) > 2: raise ValueError('too many arguments provided for X-Python3-Version: min and max only.') import operator operators = {None: operator.eq, '=': operator.eq, '>=': operator.ge, '<=': operator.le, '<<': operator.lt} vinfo = {} exact_versions = set() version_range = set(supported_versions(version_only=True)) relop_seen = False for field in vstring.split(','): field = field.strip() if field == 'all': continue if field in ('current', 'current_ext'): continue vinfo.setdefault('versions', set()) ve = re.compile(r'(>=|<=|<<|=)? *(\d\.\d)$') m = ve.match(field) try: if not m: raise ValueError('error parsing Python3-Version attribute') op, v = m.group(1), m.group(2) vmaj, vmin = v.split('.') if int(vmaj) < 3: continue if op in (None, '='): exact_versions.add(v) else: relop_seen = True filtop = operators[op] version_range = [av for av in version_range if filtop(av, v)] except Exception: raise ValueError('error parsing Python3-Version attribute') if 'versions' in vinfo: vinfo['versions'] = exact_versions if relop_seen: vinfo['versions'] = exact_versions.union(version_range) return vinfo def old_versions(version_only=False): global _old_versions if not _old_versions: try: value = read_default('old-versions') _old_versions = [s.strip() for s in value.split(',')] except ValueError: _old_versions = [] if version_only: return [v[6:] for v in _old_versions] else: return _old_versions def unsupported_versions(version_only=False): global _unsupported_versions if not _unsupported_versions: try: value = read_default('unsupported-versions') _unsupported_versions = [s.strip() for s in value.split(',')] except ValueError: _unsupported_versions = [] if version_only: return [v[6:] for v in _unsupported_versions] else: return _unsupported_versions def supported_versions(version_only=False): global _supported_versions,_default_version default_version() if not _supported_versions: try: value = read_default('supported-versions') _supported_versions = [s.strip() for s in value.split(',')] except ValueError: cmd = ['/usr/bin/apt-cache', '--no-all-versions', 'show', 'python3-all'] try: import subprocess p = subprocess.Popen(cmd, bufsize=1, shell=False, stdout=subprocess.PIPE) fd = p.stdout except ImportError: fd = os.popen(' '.join(cmd)) depends = None for line in fd: if line.startswith('Depends:'): depends = line.split(':', 1)[1].strip().split(',') fd.close() depends = [re.sub(r'\s*(\S+)[ (]?.*', r'\1', s) for s in depends] _supported_versions = depends default = _supported_versions.pop(_supported_versions.index(_default_version)) _supported_versions.sort() _supported_versions.append(default) if version_only: return [v[6:] for v in _supported_versions] else: return _supported_versions def default_version(version_only=False): global _default_version if not _default_version: _default_version = os.readlink('/usr/bin/python3') # consistency check debian_default = read_default('default-version') if not _default_version in (debian_default, os.path.join('/usr/bin', debian_default)): raise ValueError("the symlink /usr/bin/python3 does not point to the " "python3 default version. It must be reset " "to point to %s" % debian_default) _default_version = debian_default if version_only: return _default_version[6:] else: return _default_version def requested_versions(vstring, version_only=False): global _default_version default_version() versions = None vinfo = parse_versions(vstring) supported = supported_versions(version_only=True) if len(vinfo) == 1: versions = vinfo['versions'].intersection(supported) vl = [] for version in versions: vl.append(version) try: default = vl.pop(vl.index(_default_version[6:])) except: default = '' vl.sort() if default: vl.append(default) else: raise ValueError('No supported python3 versions in version string') if not versions: raise ValueError('empty set of versions') if version_only: return vl else: return ['python%s' % v for v in vl] def installed_versions(version_only=False): import glob supported = supported_versions() versions = [os.path.basename(s) for s in glob.glob('/usr/bin/python3.[0-9]') if os.path.basename(s) in supported] versions.sort() if version_only: return [v[6:] for v in versions] else: return versions class ControlFileValueError(ValueError): pass class MissingVersionValueError(ValueError): pass def extract_pyversion_attribute(fn, pkg): """read the debian/control file, extract the X-Python3-Version field.""" version = None sversion = None section = None with open(fn, encoding='utf-8') as controlfile: lines = [line.strip() for line in controlfile] for line in lines: if line == '' and section != None: if pkg == 'Source': break section = None elif line.startswith('Source:'): section = 'Source' elif line.startswith('Package: ' + pkg): section = pkg elif line.lower().startswith('x-python3-version:'): if section != 'Source': raise ValueError('attribute X-Python3-Version not in Source section') sversion = line.split(':', 1)[1].strip() if section is None: raise ControlFileValueError('not a control file') if pkg == 'Source': if sversion is None: raise MissingVersionValueError('no X-Python3-Version in control file') return sversion return version ''' def requested_versions_bis(vstring, version_only=False): versions = [] py_supported_short = supported_versions(version_only=True) for item in vstring.split(','): v=item.split('-') if len(v)>1: if not v[0]: v[0] = py_supported_short[0] if not v[1]: v[1] = py_supported_short[-1] for ver in py_supported_short: try: if version_cmp(ver,v[0]) >= 0 \ and version_cmp(ver,v[1]) <= 0: versions.append(ver) except ValueError: pass else: if v[0] in py_supported_short: versions.append(v[0]) versions.sort(version_cmp) if not versions: raise ValueError('empty set of versions') if not version_only: versions=['python'+i for i in versions] return versions ''' def main(): from optparse import OptionParser usage = '[-v] [-h] [-d|--default] [-s|--supported] [-i|--installed] ' '[-r|--requested <version string>|<control file>]' parser = OptionParser(usage=usage) parser.add_option('-d', '--default', help='print the default python3 version', action='store_true', dest='default') parser.add_option('-s', '--supported', help='print the supported python3 versions', action='store_true', dest='supported') parser.add_option('-r', '--requested', help='print the python3 versions requested by a build; ' 'the argument is either the name of a control file ' 'or the value of the X-Python3-Version attribute', action='store_true', dest='requested') parser.add_option('-i', '--installed', help='print the installed supported python3 versions', action='store_true', dest='installed') parser.add_option('-v', '--version', help='print just the version number(s)', default=False, action='store_true', dest='version_only') opts, args = parser.parse_args() program = os.path.basename(sys.argv[0]) if opts.default and len(args) == 0: try: print(default_version(opts.version_only)) except ValueError as msg: print("%s:" % program, msg) sys.exit(1) elif opts.supported and len(args) == 0: print(' '.join(supported_versions(opts.version_only))) elif opts.installed and len(args) == 0: print(' '.join(installed_versions(opts.version_only))) elif opts.requested and len(args) <= 1: if len(args) == 0: versions = 'debian/control' else: versions = args[0] try: if os.path.isfile(versions): fn = versions try: vstring = extract_pyversion_attribute(fn, 'Source') vs = requested_versions(vstring, opts.version_only) except ControlFileValueError: sys.stderr.write("%s: not a control file: %s, " % (program, fn)) sys.exit(1) except MissingVersionValueError: sys.stderr.write("%s: no X-Python3-Version in control " "file, using supported versions\n" % program) vs = supported_versions(opts.version_only) else: vs = requested_versions(versions, opts.version_only) print(' '.join(vs)) except ValueError as msg: sys.stderr.write("%s: %s\n" % (program, msg)) sys.exit(1) else: sys.stderr.write("usage: %s %s\n" % (program, usage)) sys.exit(1) if __name__ == '__main__': main()