diff --git a/doc/tutorial/tutorial_drawing.rst b/doc/tutorial/tutorial_drawing.rst
index 866e8bcdb..5249bdc3a 100644
--- a/doc/tutorial/tutorial_drawing.rst
+++ b/doc/tutorial/tutorial_drawing.rst
@@ -1,6 +1,6 @@
 .. currentmodule:: ete4.treeview
 
-Programmable Tree Drawing
+Programmable tree drawing
 =========================
 
 .. contents::
diff --git a/examples/treeview/node_style.py b/examples/treeview/node_style.py
index 80dea179e..01327f4e3 100755
--- a/examples/treeview/node_style.py
+++ b/examples/treeview/node_style.py
@@ -3,7 +3,7 @@
 
 
 def layout(node):
-    # If node is a leaf, add the nodes name and a its scientific name
+    # If node is a leaf, add the nodes name and a its scientific name.
     if node.is_leaf:
         faces.add_face_to_node(AttrFace('name'), node, column=0)
 
@@ -15,9 +15,9 @@ def get_example_tree():
     # Node style handling is no longer limited to layout functions. You
     # can now create fixed node styles and use them many times, save them
     # or even add them to nodes before drawing (this allows to save and
-    # reproduce an tree image design)
+    # reproduce an tree image design).
 
-    # Set bold red branch to the root node
+    # Set bold red branch to the root node.
     style = NodeStyle()
     style['fgcolor'] = '#0f0f0f'
     style['size'] = 0
@@ -25,11 +25,11 @@ def get_example_tree():
     style['hz_line_color'] = '#ff0000'
     style['vt_line_width'] = 8
     style['hz_line_width'] = 8
-    style['vt_line_type'] = 0 # 0 solid, 1 dashed, 2 dotted
+    style['vt_line_type'] = 0  # 0 solid, 1 dashed, 2 dotted
     style['hz_line_type'] = 0
     t.set_style(style)
 
-    #Set dotted red lines to the first two branches
+    # Set dotted red lines to the first two branches.
     style1 = NodeStyle()
     style1['fgcolor'] = '#0f0f0f'
     style1['size'] = 0
@@ -37,12 +37,12 @@ def get_example_tree():
     style1['hz_line_color'] = '#ff0000'
     style1['vt_line_width'] = 2
     style1['hz_line_width'] = 2
-    style1['vt_line_type'] = 2 # 0 solid, 1 dashed, 2 dotted
+    style1['vt_line_type'] = 2  # 0 solid, 1 dashed, 2 dotted
     style1['hz_line_type'] = 2
     t.children[0].img_style = style1
     t.children[1].img_style = style1
 
-    # Set dashed blue lines in all leaves
+    # Set dashed blue lines in all leaves.
     style2 = NodeStyle()
     style2['fgcolor'] = '#000000'
     style2['shape'] = 'circle'
@@ -50,7 +50,7 @@ def get_example_tree():
     style2['hz_line_color'] = '#0000aa'
     style2['vt_line_width'] = 2
     style2['hz_line_width'] = 2
-    style2['vt_line_type'] = 1 # 0 solid, 1 dashed, 2 dotted
+    style2['vt_line_type'] = 1  # 0 solid, 1 dashed, 2 dotted
     style2['hz_line_type'] = 1
     for l in t.leaves():
         l.img_style = style2