Use """triple double quotes""" around docstrings. https://www.python.…

…org/dev/peps/pep-0257/

dash/development/base_component.py

@@ -111,26 +111,26 @@ def _get_set_or_delete(self, id, operation, new_item=None):
     # - __len__
 
     def __getitem__(self, id):
-        '''Recursively find the element with the given ID through the tree
+        """Recursively find the element with the given ID through the tree
         of children.
-        '''
+        """
 
         # A component's children can be undefined, a string, another component,
         # or a list of components.
         return self._get_set_or_delete(id, 'get')
 
     def __setitem__(self, id, item):
-        '''Set an element by its ID
-        '''
+        """Set an element by its ID
+        """
         return self._get_set_or_delete(id, 'set', item)
 
     def __delitem__(self, id):
-        '''Delete items by ID in the tree of children
-        '''
+        """Delete items by ID in the tree of children
+        """
         return self._get_set_or_delete(id, 'delete')
 
     def traverse(self):
-        '''Yield each item in the tree'''
+        """Yield each item in the tree"""
         children = getattr(self, 'children', None)
 
         # children is just a component
@@ -149,17 +149,17 @@ def traverse(self):
                         yield t
 
     def __iter__(self):
-        '''Yield IDs in the tree of children
-        '''
+        """Yield IDs in the tree of children
+        """
         for t in self.traverse():
             if (isinstance(t, Component) and
                     getattr(t, 'id', None) is not None):
 
                 yield t.id
 
     def __len__(self):
-        '''Return the number of items in the tree
-        '''
+        """Return the number of items in the tree
+        """
         # TODO - Should we return the number of items that have IDs
         # or just the number of items?
         # The number of items is more intuitive but returning the number