1 files changed, 59 insertions, 0 deletions
diff --git a/game/python-extra/utils/objects.py b/game/python-extra/utils/objects.py
new file mode 100644
index 0000000..f22efcd
--- /dev/null
+++ b/game/python-extra/utils/objects.py
@@ -0,0 +1,59 @@
+_get_attr_raise_on_attribute_error = "RAISE ON EXCEPTION"
+
+def get_attr(obj, string_rep, default=_get_attr_raise_on_attribute_error, separator="."):
+    """ getattr via a chain of attributes like so:
+    >>> import datetime
+    >>> some_date = datetime.date.today()
+    >>> get_attr(some_date, "month.numerator.__doc__")
+    'int(x[, base]) -> integer\n\nConvert a string or number to an integer, ...
+    """
+    attribute_chain = string_rep.split(separator)
+
+    current_obj = obj
+
+    for attr in attribute_chain:
+        try:
+            current_obj = getattr(current_obj, attr)
+        except AttributeError:
+            if default is _get_attr_raise_on_attribute_error:
+                raise AttributeError(
+                    "Bad attribute \"{}\" in chain: \"{}\"".format(attr, string_rep)
+                )
+            return default
+
+    return current_obj
+
+
+class ImmutableWrapper(object):
+    _obj = None
+    _recursive = None
+
+    def __init__(self, obj, recursive):
+        self._obj = obj
+        self._recursive = recursive
+
+    def __setattr__(self, name, val):
+        if name == "_obj" and self._obj is None:
+            object.__setattr__(self, name, val)
+            return
+        elif name == "_recursive" and self._recursive is None:
+            object.__setattr__(self, name, val)
+            return
+
+        raise AttributeError("This object has been marked as immutable; you cannot set its attributes.")
+
+    def __getattr__(self, name):
+        if self._recursive:
+            return immutable(getattr(self._obj, name), recursive=self._recursive)
+
+        return getattr(self._obj, name)
+
+    def __repr__(self):
+        return "<Immutable {}: {}>".format(self._obj.__class__.__name__, self._obj.__repr__())
+
+
+def immutable(obj, recursive=True):
+    """wraps the argument in a pass-through class that disallows all attribute
+    setting. If the `recursive` flag is true, all attribute accesses will
+    return an immutable-wrapped version of the "real" attribute."""
+    return ImmutableWrapper(obj, recursive)