def tree_layout(tree_file, ps_node_list):
t = EvolTree(tree_file, format=0)
style_other = NodeStyle()
style_other['size'] = 6
style_ps = NodeStyle()
style_ps['fgcolor'] = '#ff0000'
style_ps['size'] = 6
for node in t.iter_descendants():
descendant = t.get_descendant_by_node_id(node.node_id)
if node.node_id in ps_node_list:
descendant.img_style = style_ps
else:
descendant.img_style = style_other
ts = TreeStyle()
ts.layout_fn = layout
ts.show_branch_support = False
ts.show_branch_length = False
ts.show_leaf_name = False
result_picture = os.path.join(output_dir, 'positive_selection_tree.png')
t.render(result_picture, tree_style=ts)
