Create a partial match object proxy

src/widgetastic/utils.py

@@ -545,3 +545,31 @@ def crop_string_middle(s, length=32, cropper='...'):
         return s
     half = (length - len(cropper)) / 2
     return s[:half] + cropper + s[-half - 1:]
+
+
+class partial_match(object):  # noqa
+    """Use this to wrap values to be selected using partial matching in various objects.
+
+    It proxies all ``get`` operations to the underlying ``item``.
+
+    It also proxies ``dir`` so you get the exactly same result of :py:func:`dir` as if you did it
+    on the wrapped object.
+
+    """
+    def __init__(self, item):
+        self.item = item
+
+    def __dir__(self):
+        return dir(self.item)
+
+    def __getattr__(self, attr):
+        return getattr(self.item, attr)
+
+    def __setattr__(self, attr, value):
+        if attr == 'item':
+            super(partial_match, self).__setattr__(attr, value)
+        else:
+            setattr(self.item, attr, value)
+
+    def __repr__(self):
+        return 'partial_match({!r})'.format(self.item)

testing/test_utils.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 import pytest
 
-from widgetastic.utils import nested_getattr
+from widgetastic.utils import nested_getattr, partial_match
 
 
 def test_nested_getattr_wrong_type():
@@ -30,3 +30,14 @@ class bar(object):  # noqa
 
     assert nested_getattr(Obj, 'foo.bar.lol') == 'heh'
     assert nested_getattr(Obj, ['foo', 'bar', 'lol']) == 'heh'
+
+
+def test_partial_match_wrapping():
+    value = ' foobar '
+    wrapped = partial_match(value)
+
+    assert dir(wrapped) == dir(value)
+
+    assert wrapped.item is value
+
+    assert wrapped.strip() == value.strip()