[svn r3231] Add DictMixin backport

--HG--
branch : trunk

1 files changed, 102 insertions, 0 deletions

diff --git a/src/lxml/html/_dictmixin.py b/src/lxml/html/_dictmixin.py
new file mode 100644
index 00000000..7698efcd
--- /dev/null
+++ b/src/lxml/html/_dictmixin.py
@@ -0,0 +1,102 @@
+"""
+A backport of UserDict.DictMixin for pre-python-2.4
+"""
+__all__ = ['DictMixin']
+
+try:
+    from UserDict import DictMixin
+except ImportError:
+    class DictMixin:
+        # Mixin defining all dictionary methods for classes that already have
+        # a minimum dictionary interface including getitem, setitem, delitem,
+        # and keys. Without knowledge of the subclass constructor, the mixin
+        # does not define __init__() or copy().  In addition to the four base
+        # methods, progressively more efficiency comes with defining
+        # __contains__(), __iter__(), and iteritems().
+
+        # second level definitions support higher levels
+        def __iter__(self):
+            for k in self.keys():
+                yield k
+        def has_key(self, key):
+            try:
+                value = self[key]
+            except KeyError:
+                return False
+            return True
+        def __contains__(self, key):
+            return self.has_key(key)
+
+        # third level takes advantage of second level definitions
+        def iteritems(self):
+            for k in self:
+                yield (k, self[k])
+        def iterkeys(self):
+            return self.__iter__()
+
+        # fourth level uses definitions from lower levels
+        def itervalues(self):
+            for _, v in self.iteritems():
+                yield v
+        def values(self):
+            return [v for _, v in self.iteritems()]
+        def items(self):
+            return list(self.iteritems())
+        def clear(self):
+            for key in self.keys():
+                del self[key]
+        def setdefault(self, key, default=None):
+            try:
+                return self[key]
+            except KeyError:
+                self[key] = default
+            return default
+        def pop(self, key, *args):
+            if len(args) > 1:
+                raise TypeError, "pop expected at most 2 arguments, got "\
+                                  + repr(1 + len(args))
+            try:
+                value = self[key]
+            except KeyError:
+                if args:
+                    return args[0]
+                raise
+            del self[key]
+            return value
+        def popitem(self):
+            try:
+                k, v = self.iteritems().next()
+            except StopIteration:
+                raise KeyError, 'container is empty'
+            del self[k]
+            return (k, v)
+        def update(self, other=None, **kwargs):
+            # Make progressively weaker assumptions about "other"
+            if other is None:
+                pass
+            elif hasattr(other, 'iteritems'):  # iteritems saves memory and lookups
+                for k, v in other.iteritems():
+                    self[k] = v
+            elif hasattr(other, 'keys'):
+                for k in other.keys():
+                    self[k] = other[k]
+            else:
+                for k, v in other:
+                    self[k] = v
+            if kwargs:
+                self.update(kwargs)
+        def get(self, key, default=None):
+            try:
+                return self[key]
+            except KeyError:
+                return default
+        def __repr__(self):
+            return repr(dict(self.iteritems()))
+        def __cmp__(self, other):
+            if other is None:
+                return 1
+            if isinstance(other, DictMixin):
+                other = dict(other.iteritems())
+            return cmp(dict(self.iteritems()), other)
+        def __len__(self):
+            return len(self.keys())