<s>[INST] Python try...except comma vs 'as' in except What is the difference between ',' and 'as' in except statements, eg:
try:
    pass
except Exception, exception:
    pass

and:
try:
    pass
except Exception as exception:
    pass

Is the second syntax legal in 2.6?  It works in CPython 2.6 on Windows but the 2.5 interpreter in cygwin complains that it is invalid.
If they are both valid in 2.6 which should I use?
 [/INST] The definitive document is PEP-3110: Catching Exceptions
Summary:

In Python 3.x, using as is required.
In Python 2.6+, use the as syntax, since it is far less ambiguous and forward compatible with Python 3.x.
In Python 2.5 and earlier, use the comma version, since as isn't supported.

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