[New-bugs-announce] [issue24975] Python 3.5 can't compile AST involving PEP 448 unpacking

[David Beazley]

New submission from David Beazley:

The compile() function is not able to compile an AST created from code that uses some of the new unpacking generalizations in PEP 448.  Example:

code = '''                                                                     
a = { 'x':1, 'y':2 }
b = { **a, 'z': 3 }
'''

# Works
ccode = compile(code, '', 'exec')

# Crashes
import ast
tree = ast.parse(code)
ccode = compile(tree, '', 'exec')

# ----------------------------------

Error Traceback:

Traceback (most recent call last):
  File "bug.py", line 11, in <module>
    ccode = compile(tree, '', 'exec')
ValueError: None disallowed in expression list

Note:  This bug makes it impossible to try generalized unpacking examples interactively in IPython.

----------
components: Library (Lib)
messages: 249442
nosy: dabeaz
priority: normal
severity: normal
status: open
title: Python 3.5 can't compile AST involving PEP 448 unpacking
type: crash
versions: Python 3.5

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue24975>
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