Rename skip to filter and reverse logic

attr/_funcs.py

@@ -30,7 +30,7 @@ def fields(cl):
     return copy.deepcopy(attrs)
 
 
-def asdict(inst, recurse=True, skip=None):
+def asdict(inst, recurse=True, filter=None):
     """
     Return the ``attrs`` attribute values of *i* as a dict.  Optionally recurse
     into other ``attrs``-decorated classes.
@@ -40,10 +40,11 @@ def asdict(inst, recurse=True, skip=None):
     :param recurse: Recurse into classes that are also ``attrs``-decorated.
     :type recurse: bool
 
-    :param skip: A filter function that causes elements to be left out if it
-        returns ``True``.  Is called with the :class:`attr.Attribute` as the
-        first argument and the value as the second argument.
-    :type skip: callable
+    :param filter: A callable whose return code deteremines whether an
+        attribute or element is included (``True``) or dropped (``False``).  Is
+        called with the :class:`attr.Attribute` as the first argument and the
+        value as the second argument.
+    :type filer: callable
 
     :rtype: :class:`dict`
     """
@@ -51,14 +52,14 @@ def asdict(inst, recurse=True, skip=None):
     rv = {}
     for a in attrs:
         v = getattr(inst, a.name)
-        if skip is not None and skip(a, v):
+        if filter is not None and not filter(a, v):
             continue
         if recurse is True:
             if has(v.__class__):
-                rv[a.name] = asdict(v, recurse=True, skip=skip)
+                rv[a.name] = asdict(v, recurse=True, filter=filter)
             elif isinstance(v, (tuple, list, set)):
                 rv[a.name] = [
-                    asdict(i, recurse=True, skip=skip)
+                    asdict(i, recurse=True, filter=filter)
                     if has(i.__class__) else i
                     for i in v
                 ]

docs/examples.rst

@@ -73,7 +73,7 @@ When you have a class with data, it often is very convenient to transform that c
    {'y': 2, 'x': 1}
 
 Some fields cannot or should not be transformed.
-For that, :func:`attr.asdict` offers a callback that decides whether an attribute should be skipped:
+For that, :func:`attr.asdict` offers a callback that decides whether an attribute should be included:
 
 .. doctest::
 
@@ -86,7 +86,7 @@ For that, :func:`attr.asdict` offers a callback that decides whether an attribut
    ...     password = attr.ib()
    >>> attr.asdict(UserList([User("jane@doe.invalid", "s33kred"),
    ...                       User("joe@doe.invalid", "p4ssw0rd")]),
-   ...             skip=lambda attr, value: attr.name == "password")
+   ...             filter=lambda attr, value: attr.name != "password")
    {'users': [{'email': 'jane@doe.invalid'}, {'email': 'joe@doe.invalid'}]}
 
 

tests/test_funcs.py

@@ -92,7 +92,7 @@ class TestAsDict(object):
             C(3, 4),
         ))
 
-    def test_skip(self):
+    def test_filter(self):
         """
         Attributes that are supposed to be skipped are skipped.
         """
@@ -101,7 +101,7 @@ class TestAsDict(object):
         } == asdict(C(
             C(1, 2),
             C(3, 4),
-        ), skip=lambda a, v: a.name == "y")
+        ), filter=lambda a, v: a.name != "y")
 
     @pytest.mark.parametrize("container", [
         list,