Re: [Jython-dev] exec <file> in <dictionary>

[<bc...@wo...>]

[brian zimmer]

>I was trying to use the following syntax in Jython but I get an exception:
>
>>>> t = {}
>>>> exec open(filename) in t
>
>Traceback (innermost last):
>  File "install.py", line 381, in ?
>  File "install.py", line 47, in run
>  File "install.py", line 71, in detectComponents
>  File "install.py", line 89, in readProperties
>TypeError: exec: argument 1 must be string or code object
>
>This works in CPython and appears to be part of the spec:
>
>"The first expression should evaluate to either a string, an open file
>object, or a code object. ...  If it is an open file, the file is parsed
>until EOF and executed."
>
>http://python.org/doc/current/ref/exec.html

Yep, and jython should support this as well.

>Additionally, in CPython 2.0, if the file is closed it is re-opened and
>executed.

I can't reproduce this behaviour in CPython 2.0. Instead it appears that
CPython treats a closed file as an empty file (no exception is thrown).
Do you have an example that show that the file is reopened?

>Given this, I've enclosed a working diff which mimics the exact behaviour of
>CPython 2.0.

If I'm correct regarding the reopen thing, I would rather do something
like:

                if (fp.closed)
                    return;
                contents = fp.read().toString();

to avoid the "I/O operation on closed file" exception.

regards,
finn