tweaks

examples/how_to_write_docstring.py

@@ -14,17 +14,17 @@ def _cos(x):
 
 
 # a function with a complete docstring
-def cos(x: float = 0.):
+def cos(x: float = 0.) -> float:
     """ cosine function
 
     Parameters
     ----------
-    x :
+    x : float
         x values
 
     Returns
     -------
-    cos(x)
+    cos(x) : float
 
     Examples
     --------