-

cool-RR · cool-RR · commit 35cc08599e1e · 2013-11-19T00:04:48.000+02:00
diff --git a/source_py2/python_toolbox/misc_tools/__init__.py b/source_py2/python_toolbox/misc_tools/__init__.py
@@ -8,7 +8,8 @@
     _ascii_variable_pattern, is_legal_ascii_variable_name,
     is_magic_variable_name, get_actual_type, is_number, identity_function,
     do_nothing, OwnNameDiscoveringDescriptor, find_clear_place_on_circle,
-    general_sum, general_product, is_legal_email_address, is_type, NonInstatiable
+    general_sum, general_product, is_legal_email_address, is_type, NonInstatiable,
+    repeat_getattr
 )
 from . import name_mangling
 from .proxy_property import ProxyProperty
diff --git a/source_py2/python_toolbox/misc_tools/misc_tools.py b/source_py2/python_toolbox/misc_tools/misc_tools.py
@@ -284,4 +284,21 @@ class NonInstatiable(object):
     constants and settings.
     '''
     def __new__(self, *args, **kwargs):
-        raise RuntimeError('This class may not be instatiated.')
+        raise RuntimeError('This class may not be instatiated.')    
+    
+def repeat_getattr(thing, query):
+    '''
+    Perform a repeated `getattr` operation.
+    
+    i.e., when given `repeat_getattr(x, '.y.z')`, will return `x.y.z`.
+    '''
+    if not query:
+        return thing
+    assert isinstance(query, str)
+    if not query.startswith('.'):
+        raise Exception('''`query` must start with '.', e.g. '.foo.bar.baz'.''')
+    attribute_names = filter(None, query.split('.'))
+    current = thing 
+    for attribute_name in attribute_names:
+        current = getattr(current, attribute_name)
+    return current
diff --git a/source_py2/python_toolbox/temp_value_setting/temp_value_setter.py b/source_py2/python_toolbox/temp_value_setting/temp_value_setter.py
@@ -7,7 +7,6 @@
 See its documentation for more details.
 '''
 
-from python_toolbox import address_tools
 from python_toolbox.context_management import ContextManager
 
 
diff --git a/source_py2/test_python_toolbox/test_address_tools/test_describe.py b/source_py2/test_python_toolbox/test_address_tools/test_describe.py
@@ -10,8 +10,7 @@
 from python_toolbox.temp_value_setting import TempValueSetter
 
 import python_toolbox
-from python_toolbox.address_tools import (describe,
-                                                  resolve)
+from python_toolbox.address_tools import describe, resolve
 
 # todo: Make test that when a root or namespace is given, it's top priority to
 # use it, even if it prevents shorterning and results in an overall longer
diff --git a/source_py2/test_python_toolbox/test_misc_tools/test_name_mangling/test_repeat_getattr.py b/source_py2/test_python_toolbox/test_misc_tools/test_name_mangling/test_repeat_getattr.py
@@ -0,0 +1,34 @@
+# Copyright 2009-2013 Ram Rachum.
+# This program is distributed under the MIT license.
+
+'''Testing module for name demangling.'''
+
+from python_toolbox import cute_testing
+
+from python_toolbox.misc_tools import repeat_getattr
+
+
+class Object(object):
+    def __init__(self, tag):
+        self.tag = tag
+    __eq__ = lambda self, other: (self.tag == other.tag)
+        
+
+x = Object('x')
+x.y = Object('y')
+x.y.z = Object('z')
+x.y.meow = Object('meow')
+        
+
+def test():
+    assert repeat_getattr(x, None) == repeat_getattr(x, '') == x
+    with cute_testing.RaiseAssertor():
+        repeat_getattr(x, 'y')
+        
+    assert x != x.y != x.y.z != x.y.meow
+    assert repeat_getattr(x, '.y') == x.y
+    assert repeat_getattr(x, '.y.z') == x.y.z
+    assert repeat_getattr(x, '.y.meow') == x.y.meow
+    
+    assert repeat_getattr(x.y, '.meow') == x.y.meow
+    assert repeat_getattr(x.y, '.z') == x.y.z
