Const(None) in compiler.ast.Return.value

[aligrudi]

BPO	1715581

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2007-06-05.17:47:51.000>
created_at = <Date 2007-05-09.09:53:29.000>
labels = ['library']
title = 'Const(None) in compiler.ast.Return.value'
updated_at = <Date 2007-06-05.17:47:51.000>
user = 'https://bugs.python.org/aligrudi'

bugs.python.org fields:

activity = <Date 2007-06-05.17:47:51.000>
actor = 'collinwinter'
assignee = 'collinwinter'
closed = True
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2007-05-09.09:53:29.000>
creator = 'aligrudi'
dependencies = []
files = []
hgrepos = []
issue_num = 1715581
keywords = []
message_count = 2.0
messages = ['31990', '31991']
nosy_count = 2.0
nosy_names = ['collinwinter', 'aligrudi']
pr_nums = []
priority = 'normal'
resolution = 'wont fix'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue1715581'
versions = ['Python 2.5']

[aligrudi]

The problem happens when::

  import compiler

  class Visitor(object):
      def visitReturn(self, node):
          print node.value

  source = """
  def f():
      return
  """
  compiler.walk(compiler.parse(source), Visitor())

I think the value of node.value should have been None instead of
Const(None) as it is for most other nodes when an optional part is
missing. The same problem (getting Const(None) instead of None)
exists for Sliceobj.nodes[i] and Discard.expr.

[collinwinter]

"return" is syntactic shorthand for "return None", so Const(None) is the right value; same thing for Sliceobj. This isn't a bug.