diff --git a/ausankey/ausankey.py b/ausankey/ausankey.py
index 3f057ad..e727887 100644
--- a/ausankey/ausankey.py
+++ b/ausankey/ausankey.py
@@ -184,7 +184,7 @@ def sankey(
             weight_strt = data[2 * ii + 1][ind_this & ~ind_prev & ind_next].sum()
             node_sizes[ii][lbl] = weight_cont + weight_only + max(weight_stop, weight_strt)
         node_sizes[ii] = sort_dict(node_sizes[ii], sort)
-    
+
     for ii in range(num_side):
         if ii == 0:
             ind_prev = data[2 * ii + 1].notnull()
@@ -334,18 +334,18 @@ def _sankey(
     Some special-casing is used for plotting/labelling differently
     for the first and last cases.
     """
-    
+
     if flow_edge:
         edge_alpha = 1
         edge_lw = 1
     else:
         edge_alpha = alpha
         edge_lw = 0
-    
+
     labelind = 2 * ii
     weightind = 2 * ii + 1
 
-    if ii < num_flow-1:
+    if ii < num_flow - 1:
         labels_lr = [
             pd.Series(data[labelind]),
             pd.Series(data[labelind + 2]),
@@ -386,8 +386,8 @@ def _sankey(
         ]
     else:
         bar_lr = [
-            sort_nodes(labels_lr[0],node_sizes[ii]),
-            sort_nodes(labels_lr[1],node_sizes[ii+1]),
+            sort_nodes(labels_lr[0], node_sizes[ii]),
+            sort_nodes(labels_lr[1], node_sizes[ii + 1]),
         ]
 
     # check labels
@@ -423,7 +423,7 @@ def _sankey(
         vscale = 0
 
     barpos = [{}, {}]
-    node_voffset = [{},{}]
+    node_voffset = [{}, {}]
     for lr in [0, 1]:
         for i, label in enumerate(bar_lr[lr]):
             barpos[lr][label] = {}
@@ -509,7 +509,6 @@ def draw_bar(x, dx, y, dy, label):
     # Plot flows
     for lbl_l in bar_lr[0]:
         for lbl_r in bar_lr[1]:
-            
             lind = labels_lr[0] == lbl_l
             rind = labels_lr[1] == lbl_r
             if not any(lind & rind):
@@ -527,10 +526,10 @@ def draw_bar(x, dx, y, dy, label):
             # so next strip starts at the right place
             barpos[0][lbl_l]["bot"] += lbar
             barpos[1][lbl_r]["bot"] += rbar
-    
+
             xx = np.linspace(x_left, x_right, len(ys_d))
             cc = combine_colours(color_dict[lbl_l], color_dict[lbl_r], len(ys_d))
-    
+
             for jj in range(len(ys_d) - 1):
                 ax.fill_between(
                     xx[[jj, jj + 1]],
@@ -602,8 +601,10 @@ def draw_bar(x, dx, y, dy, label):
                     fontsize=fontsize,
                 )
 
+
 ###########################################
 
+
 def sort_nodes(lbl, node_sizes):
     """creates a sorted list of labels by their summed weights"""
 
@@ -618,9 +619,11 @@ def sort_nodes(lbl, node_sizes):
     )
 
     return list(dict(sort_arr).keys())
-    
+
+
 ###########################################
 
+
 def sort_dict(lbl, sorting):
     """creates a sorted list of labels by their summed weights"""
 
@@ -633,7 +636,6 @@ def sort_dict(lbl, sorting):
     else:
         s = 0
 
-        
     sort_arr = sorted(
         lbl.items(),
         key=lambda item: s * item[1],