Merge pull request #51 from ucd-cws/pr/50

New "insert" functionality via Ryan Dalton

README.md

@@ -63,6 +63,7 @@ Change list items
 metadata.tags = ["tag1", "tag2"]
 metadata.tags[1] = "another tag"
 metadata.tags.append("new tag")
+metadata.tags.insert(0, "first tag")
 metadata.tags.remove("tag1")
 metadata.tags.pop()
 ```

arcpy_metadata/metadata_constructors.py

@@ -33,6 +33,15 @@ def append(self, value):
         """
         self.list_items.append(value)
 
+    def insert(self, index, value):
+        """
+        Insert given item to list at specified index location. Functions similar to Python list inserts
+        :param index: location in list to insert
+        :param value: the value to insert into the list
+        :return:
+        """
+        self.list_items.insert(index, value)
+
     def remove(self, value):
         """
         Remove given item from list
@@ -278,6 +287,20 @@ def append(self, item):
         self.current_items.append(element)
         self.element._children = self.current_items
 
+    def insert(self, index, item):
+        """
+            Inserts an individual item to the section at specified index location
+            :param index: location in list to insert
+            :param item: the text that will be added to the multi-item section, wrapped in the appropriate tag
+                configured on parent object
+            :return:
+        """
+
+        element = ET.Element(self.tag_name)
+        element.text = item
+        self.current_items.insert(index, element)
+        self.element._children = self.current_items
+
     def pop(self):
         """
         Remove the last element in element tree