"""namespace module"""
__all__ = ("Namespace", "as_namespace")
from collections import Mapping, Sequence
class _Dummy: ...
CLASS_ATTRS = dir(_Dummy)
del _Dummy
class Namespace(dict):
"""A dict subclass that exposes its items as attributes.
Warning: Namespace instances do not have direct access to the
dict methods.
"""
def __init__(self, obj={}):
super().__init__(obj)
def __dir__(self):
return tuple(self)
def __repr__(self):
return "%s(%s)" % (type(self).__name__, super().__repr__())
def __getattribute__(self, name):
try:
return self[name]
except KeyError:
msg = "'%s' object has no attribute '%s'"
raise AttributeError(msg % (type(self).__name__, name))
def __setattr__(self, name, value):
self[name] = value
def __delattr__(self, name):
del self[name]
#------------------------
# "copy constructors"
@classmethod
def from_object(cls, obj, names=None):
if names is None:
names = dir(obj)
ns = {name:getattr(obj, name) for name in names}
return cls(ns)
@classmethod
def from_mapping(cls, ns, names=None):
if names:
ns = {name:ns[name] for name in names}
return cls(ns)
@classmethod
def from_sequence(cls, seq, names=None):
if names:
seq = {name:val for name, val in seq if name in names}
return cls(seq)
#------------------------
# static methods
@staticmethod
def hasattr(ns, name):
try:
object.__getattribute__(ns, name)
except AttributeError:
return False
return True
@staticmethod
def getattr(ns, name):
return object.__getattribute__(ns, name)
@staticmethod
def setattr(ns, name, value):
return object.__setattr__(ns, name, value)
@staticmethod
def delattr(ns, name):
return object.__delattr__(ns, name)
def as_namespace(obj, names=None):
# functions
if isinstance(obj, type(as_namespace)):
obj = obj()
# special cases
if isinstance(obj, type):
names = (name for name in dir(obj) if name not in CLASS_ATTRS)
return Namespace.from_object(obj, names)
if isinstance(obj, Mapping):
return Namespace.from_mapping(obj, names)
if isinstance(obj, Sequence):
return Namespace.from_sequence(obj, names)
# default
return Namespace.from_object(obj, names)
Diff to Previous Revision
--- revision 2 2011-10-01 05:45:46
+++ revision 3 2011-10-03 21:12:41
@@ -58,7 +58,7 @@
@classmethod
def from_sequence(cls, seq, names=None):
if names:
- seq = {name:val for name, val in obj if name in names}
+ seq = {name:val for name, val in seq if name in names}
return cls(seq)
#------------------------
