Files
deb-python-pecan/pecan/configuration.py

189 lines
4.7 KiB
Python

import re
import inspect
import os
import string
IDENTIFIER = re.compile(r'[a-z_](\w)*$', re.IGNORECASE)
STRING_FORMAT = re.compile(r'{pecan\.conf(?P<var>([.][a-z_][\w]*)+)+?}', re.IGNORECASE)
class ConfigDict(dict):
pass
class ConfigString(object):
def __init__(self, format_string):
self.raw_string = format_string
def __call__(self):
retval = self.raw_string
for candidate in STRING_FORMAT.finditer(self.raw_string):
var = candidate.groupdict().get('var','')
try:
obj = _runtime_conf
for dotted_part in var.split('.'):
if dotted_part == '':
continue
obj = getattr(obj, dotted_part)
retval = retval.replace(candidate.group(), str(obj))
except AttributeError, e:
raise AttributeError, 'Cannot substitute \'%s\' using the current configuration' % candidate.group()
return retval
def __str__(self):
return self.raw_string
@staticmethod
def contains_formatting(value):
return STRING_FORMAT.match(value)
class Config(object):
def __init__(self, conf_dict={}):
self.update(conf_dict)
def update(self, conf_dict):
if isinstance(conf_dict, dict):
iterator = conf_dict.iteritems()
else:
iterator = iter(conf_dict)
for k,v in iterator:
if not IDENTIFIER.match(k):
raise ValueError('\'%s\' is not a valid indentifier' % k)
cur_val = self.__dict__.get(k)
if isinstance(cur_val, Config):
cur_val.update(conf_dict[k])
else:
self[k] = conf_dict[k]
def update_with_module(self, module):
self.update(conf_from_module(module))
def __getitem__(self, key):
return self.__dict__[key]
def __setitem__(self, key, value):
if isinstance(value, dict) and not isinstance(value, ConfigDict):
if value.get('__force_dict__'):
del value['__force_dict__']
self.__dict__[key] = ConfigDict(value)
else:
self.__dict__[key] = Config(value)
elif isinstance(value, str) and ConfigString.contains_formatting(value):
self.__dict__[key] = ConfigString(value)
else:
self.__dict__[key] = value
def __iter__(self):
return self.__dict__.iteritems()
def __dir__(self):
return self.__dict__.keys()
def __repr__(self):
return 'Config(%s)' % str(self.__dict__)
def __call__(self):
for k,v in self:
if isinstance(v, Config):
v()
elif hasattr(v, '__call__'):
self.__dict__[k] = v()
return self
def conf_from_module(module):
if isinstance(module, str):
module = import_module(module)
module_dict = dict(inspect.getmembers(module))
return conf_from_dict(module_dict)
def conf_from_file(filepath):
abspath = os.path.abspath(os.path.expanduser(filepath))
conf_dict = {}
execfile(abspath, globals(), conf_dict)
conf_dict['__file__'] = abspath
return conf_from_dict(conf_dict)
def conf_from_dict(conf_dict):
conf = Config()
# set the configdir
conf_dir = os.path.dirname(conf_dict.get('__file__', ''))
if conf_dir == '':
conf_dir = os.getcwd()
conf['__conffile__'] = conf_dict.get('__file__')
conf['__confdir__'] = conf_dir + '/'
for k,v in conf_dict.iteritems():
if k.startswith('__'):
continue
elif inspect.ismodule(v):
continue
conf[k] = v
conf()
return conf
def import_module(conf):
if conf.endswith('.py'):
conf = conf[:-3]
if '.' in conf:
parts = conf.split('.')
name = '.'.join(parts[:-1])
fromlist = parts[-1:]
try:
module = __import__(name, fromlist=fromlist)
conf_mod = getattr(module, parts[-1])
except ImportError, e:
raise ImportError('No module named %s' % conf)
except AttributeError, e:
raise ImportError('No module named %s' % conf)
else:
name = conf
try:
conf_mod = __import__(name)
except ImportError, e:
raise ImportError('No module named %s' % conf)
return conf_mod
def initconf():
import default_config
conf = conf_from_module(default_config)
conf()
return conf
def set_config(name):
if '/' in name:
_runtime_conf.update(conf_from_file(name))
else:
_runtime_conf.update_with_module(name)
_runtime_conf = initconf()