Move DD code into its own directory (#6)

reference/ddtrace/utils/attrdict.py

@@ -0,0 +1,37 @@
+class AttrDict(dict):
+    """
+    dict implementation that allows for item attribute access
+
+
+    Example::
+
+       data = AttrDict()
+       data['key'] = 'value'
+       print(data['key'])
+
+       data.key = 'new-value'
+       print(data.key)
+
+       # Convert an existing `dict`
+       data = AttrDict(dict(key='value'))
+       print(data.key)
+    """
+
+    def __getattr__(self, key):
+        if key in self:
+            return self[key]
+        return object.__getattribute__(self, key)
+
+    def __setattr__(self, key, value):
+        # 1) Ensure if the key exists from a dict key we always prefer that
+        # 2) If we do not have an existing key but we do have an attr, set that
+        # 3) No existing key or attr exists, so set a key
+        if key in self:
+            # Update any existing key
+            self[key] = value
+        elif hasattr(self, key):
+            # Allow overwriting an existing attribute, e.g. `self.global_config = dict()`
+            object.__setattr__(self, key, value)
+        else:
+            # Set a new key
+            self[key] = value