Fixing style errors.

Author: stickler-ci

xarray/plot/plot.py

@@ -221,7 +221,7 @@ def line(darray, *args, **kwargs):
             raise ValueError('y ' + error_msg)
 
         if x is not None and y is not None and x == y:
-            raise ValueError('Cannot make a plot with x=%r and y=%r' % (x,y))
+            raise ValueError('Cannot make a plot with x=%r and y=%r' % (x, y))
 
         if (x is None and y is None) or x == dim or y is darray.name:
             xplt = darray.coords[dim]
@@ -248,7 +248,7 @@ def line(darray, *args, **kwargs):
         else:
             if x is not None and x is not darray.name:
                 raise ValueError('Cannot make a line plot with x=%r, y=%r and hue=%r'
-                                 % (x,y,hue))
+                                 % (x, y, hue))
 
             ylabel, huelabel = _infer_xy_labels(darray=darray, x=y, y=hue)
             xlabel = darray.name