Add some comments

dstansby · dstansby · commit 665b399305ff · 2018-02-10T22:18:15.000Z
diff --git a/lib/matplotlib/units.py b/lib/matplotlib/units.py
@@ -65,13 +65,19 @@ def _accepts_units(convert_x, convert_y):
     def decorator(func):
         def wrapper(*args, **kwargs):
             axes = args[0]
+            # Bind the incoming arguments to the function signature
             bound_args = inspect.signature(func).bind(*args, **kwargs)
+            # Get the original arguments - these will be modified later
             arguments = bound_args.arguments
+            # Check for data kwarg
             has_data = (('data' in arguments) and
                         (arguments['data'] is not None))
             if has_data:
                 data = arguments['data']
 
+            # Loop through each argument to be converted, update the axis
+            # unit info, convert argument, and replace in *arguments* with
+            # converted values
             for arg in convert_x:
                 if has_data and arguments[arg] in data:
                     data_arg = arguments[arg]
@@ -100,8 +106,10 @@ def wrapper(*args, **kwargs):
 
             if has_data:
                 arguments['data'] = data
+            # Update the arguments with converted values
             bound_args.arguments = arguments
 
+            # Give updated values to the original function
             args = bound_args.args
             kwargs = bound_args.kwargs
             return func(*args, **kwargs)
