这在Python 3.9中已修复！
https://github.com/we-like-parsers/pegen/issues/229
with (Dummy() as a, Dummy() as b, # my comment explaining why I wanted Dummy() as c Dummy() as c): pass
这证明它有效：
Python 3.9.0a6 (default, Jun 20 2020, 14:52:53) Type 'copyright', 'credits' or 'license' for more informationIPython 7.15.0 -- An enhanced Interactive Python. Type '?' for help.In [3]: with (open('x') ...: as f): ...: pass ...: ---------------------------------------------------------------------------FileNotFoundError Traceback (most recent call last)<ipython-input-3-47d5a51db08b> in <module>----> 1 with (open('x') 2 as f): 3 pass 4FileNotFoundError: [Errno 2] No such file or directory: 'x'In [4]: Do you really want to exit ([y]/n)? ywPython 3.8.2 (default, May 8 2020, 20:08:31) Type 'copyright', 'credits' or 'license' for more informationIPython 7.15.0 -- An enhanced Interactive Python. Type '?' for help.In [1]: with (open('x') ...: as f): ...: pass File "<ipython-input-1-e538abd13934>", line 2 as f): ^SyntaxError: invalid syntax
