Broken on python 3.8 about pawk

[SpotlightKid]

This fixes it for me:

diff --git a/pawk.py b/pawk.py
index 7c507ee..33e8675 100644
--- a/pawk.py
+++ b/pawk.py
@@ -53,7 +53,7 @@ def save_last_expression(tree, var_name=RESULT_VAR_NAME):
     body = tree.body
     node = body[-1] if len(body) else None
     body.insert(0, ast.Assign(targets=[ast.Name(id=var_name, ctx=ast.Store())],
-                              value=ast.Name(id="None", ctx=ast.Load())))
+                              value=ast.Constant(None)))
     if node and isinstance(node, ast.Expr):
         body[-1] = ast.copy_location(ast.Assign(
             targets=[ast.Name(id=var_name, ctx=ast.Store())], value=node.value), node)

For explanation see: https://bugs.python.org/issue40870