Source code for pycopia.basicconfig

#!/usr/bin/python2.7
# vim:ts=4:sw=4:softtabstop=4:smarttab:expandtab
#
#    Copyright (C) 1999-  Keith Dart <keith@kdart.com>
#
#    This library is free software; you can redistribute it and/or
#    modify it under the terms of the GNU Lesser General Public
#    License as published by the Free Software Foundation; either
#    version 2.1 of the License, or (at your option) any later version.
#
#    This library is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
#    Lesser General Public License for more details.

from __future__ import absolute_import
from __future__ import print_function
from __future__ import unicode_literals
from __future__ import division
"""
Basic configuration holder objects.


"""

import sys, os
import warnings



if sys.version_info.major == 3:
    def execfile(fn, glbl, loc):
        exec(open(fn).read(), glbl, loc)
else: # python 2
    execfile = execfile


class BasicConfigError(Exception):
    pass

class ConfigLockError(BasicConfigError):
    pass

class ConfigReadError(BasicConfigError):
    pass


[docs]class ConfigHolder(dict): """ConfigHolder() Holds named configuration information. For convenience, it maps attribute access to the real dictionary. This object is lockable, use the 'lock' and 'unlock' methods to set its state. If locked, new keys or attributes cannot be added, but existing ones may be changed.""" def __init__(self, init={}, name=None): name = name or self.__class__.__name__.lower() dict.__init__(self, init) dict.__setattr__(self, "_locked", 0) dict.__setattr__(self, "_name", name) def __getstate__(self): return self.__dict__.items() def __setstate__(self, items): for key, val in items: self.__dict__[key] = val def __repr__(self): return "%s(%s)" % (self.__class__.__name__, dict.__repr__(self)) def __str__(self): n = self._name s = ["{}(name={!r}):".format(self.__class__.__name__, n)] s = s + [" {}.{} = {!r}".format(n, it[0], it[1]) for it in self.items()] s.append("\n") return "\n".join(s) def __setitem__(self, key, value): if self._locked and not key in self: raise ConfigLockError("setting attribute on locked config holder") return super(ConfigHolder, self).__setitem__(key, value) def __getitem__(self, name): return super(ConfigHolder, self).__getitem__(name) def __delitem__(self, name): return super(ConfigHolder, self).__delitem__(name) __getattr__ = __getitem__ __setattr__ = __setitem__ # __delattr__ = __delitem__ def lock(self): dict.__setattr__(self, "_locked", 1) def unlock(self): dict.__setattr__(self, "_locked", 0) def islocked(self): return self._locked def copy(self): ch = ConfigHolder(self) if self.islocked(): ch.lock() return ch def add_section(self, name): self.name = SECTION(name)
class SECTION(ConfigHolder): def __init__(self, name): super(SECTION, self).__init__(name=name) def __repr__(self): return super(SECTION, self).__str__() class BasicConfig(ConfigHolder): def mergefile(self, filename, globalspace=None): """Merge in a Python syntax configuration file that should assign global variables that become keys in the configuration. Returns True if file read OK, False otherwise.""" if os.path.isfile(filename): gb = globalspace or {} # temporary global namespace for config files. gb["SECTION"] = SECTION gb["sys"] = sys # in case config stuff needs these. gb["os"] = os def include(fname): execfile(get_pathname(fname), gb, self) gb["include"] = include try: execfile(filename, gb, self) except: ex, val, tb = sys.exc_info() warnings.warn("BasicConfig: error reading %s: %s (%s)." % (filename, ex, val)) return False else: return True else: return False def get_pathname(basename): basename = os.path.expandvars(os.path.expanduser(basename)) if basename.find(os.sep) < 0: basename = os.path.join(os.sep, "etc", "pycopia", basename) return basename # main function for getting a configuration file. gets it from the common # configuration location (/etc/pycopia), but if a full path is given then # use that instead. def get_config(fname, initdict=None, globalspace=None, **kwargs): fname = get_pathname(fname) cf = BasicConfig() if cf.mergefile(fname, globalspace): if initdict: cf.update(initdict) cf.update(kwargs) return cf else: raise ConfigReadError("did not successfully read %r." % (fname,))
[docs]def check_config(fname): """check_config(filename) -> bool Check is a config file can be read without errors and contains something. """ fname = get_pathname(fname) cf = BasicConfig() if cf.mergefile(fname): return bool(cf) else: return False
def _test(argv): cf = get_config("config_test.conf") print (cf) if __name__ == "__main__": _test(sys.argv)