"""Utility methods for Cloud Storage."""
import functools
_SENTINEL = object()
[docs]def rgetattr(obj, attr, default=_SENTINEL):
"""Get a nested named attribute from an object.
Example: ::
b = type('B', (), {'c': True})()
a = type('A', (), {'b': b})()
# True
Source:
`getattr-and-setattr-on-nested-objects <https://stackoverflow.com/questions/
31174295/getattr-and-setattr-on-nested-objects/31174427>`__
:param obj: Object.
:type obj: object
:param attr: Dot notation attribute name.
:type attr: str
:param default: (optional) Sentinel value, defaults to :class:`object()`.
:type default: object
:return: Attribute value.
:rtype: object
"""
if default is _SENTINEL:
_getattr = getattr
else:
def _getattr(obj_, name):
return getattr(obj_, name, default)
return functools.reduce(_getattr, [obj] + attr.split("."))
[docs]def rsetattr(obj, attr, val):
"""Sets the nested named attribute on the given object to the specified
value.
Example: ::
b = type('B', (), {'c': True})()
a = type('A', (), {'b': b})()
rsetattr(a, 'b.c', False)
# False
Source: `getattr-and-setattr-on-nested-objects <https://stackoverflow.com/
questions/31174295/getattr-and-setattr-on-nested-objects/31174427>`__
:param obj: Object.
:type obj: object
:param attr: Dot notation attribute name.
:type attr: str
:param val: Value to set.
:type val: object
:return: NoneType
:rtype: None
"""
pre, _, post = attr.rpartition(".")
return setattr(rgetattr(obj, pre) if pre else obj, post, val)