def check_init_obj(self, params=None):
""" check if the function used for init can be used in this API
-> must allow **kwargs and *args.
All arguments must have a value: either a default one or specified in
the input dict *params*
"""
args, varargs, varkw, defaults = getargspec(self._init_obj)
if varkw is not None: # we don't want **kwargs arguments
raise Exception(
"Keywords dict argument (eg **kwargs) " "not supported (init function:%s)." % str(self._init_obj)
)
if varargs is not None: # we don't want *args arguments
raise Exception(
"Positional list argument (eg *args) " " not supported (init function:%s)" % str(self._init_obj)
)
if args[0] == "self":
args = args[1:]
if params is not None:
if set(params.keys()) != set(args):
raise Exception(
"Some arguments do not " "have a value: %s" % (str(set(args).difference(params.keys())))
)
elif len(args) - 1 != len(defaults):
pos_args = args[: len(args) - len(defaults)]
print "pos_args:", pos_args
raise Exception(
'In init function "%s.%s", some arguments are '
"not keywords arguments: %s" % (str(self.__class__), str(self._init_obj.__name__), ",".join(pos_args))
)
def set_init(self, init_obj, **init_params):
""" Override init function with *init_obj* and use *init_params*
as new init parameters. *init_obj* must return an instance of the
same class as the current object. Useful when the object is not
instanciated via its __init__ function but eg a static method.
"""
self._init_obj = init_obj
args, varargs, varkw, defaults = getargspec(self._init_obj)
self.check_init_obj(init_params)
self._init_parameters = dict((k, copy(v)) for k, v in init_params.iteritems())
for ip in self._init_parameters:
if ip not in args:
raise Exception(
'Init parameter "%s" is not an argument of '
'init function "%s". Args are: %s' % (ip, str(self._init_obj), ",".join(args))
)