why doesn't this filter the warning?

[Terry Carroll]

If I do the following code, whether in the interactive session or in a
file, I get a FutureWarning:

x = 0xffffffff <stdin>:1: FutureWarning: hex/oct constants > sys.maxint will return
positive values in Python 2.4 and up

Okay; that's expected. No problem, I'll just turn off the
FutureWarning. Here's the results from within an interactive session:
import warnings
warnings.filterwarnings('ignore', "hex/oct constants", FutureWarning)
x = 0xffffffff

Note that no warning is produced. Great; that's what I wanted.

But now, the same thing, but executing a file, rather than
interactively:

[begin-quote]
C:\test\misc>cat testfw.py
import warnings
warnings.filterwarnings('ignore', "hex/oct constants", FutureWarning)
x = 0xffffffff

C:\test\misc>python testfw.py
testfw.py:3: FutureWarning: hex/oct constants > sys.maxint will return
positive values in Python 2.4 and up
x = 0xffffffff
[end-quote]

Why won't the filterwarnings call suppress this?

[Jeff Epler]

On Sun, Oct 17, 2004 at 06:18:06PM -0700, Terry Carroll wrote:

Why won't the filterwarnings call suppress this?

The warning is produced at the time the code is *parsed*, not when it is
*executed*. You could suppress the warning in an imported module by
putting the suppression above the import of the problem module, for
instance.

This use of 'compile' to produce a code object which is subsequently
called demonstrates the point:

c = compile("0xffffffff", "<string>", "eval") <string>:0: FutureWarning: hex/oct constants > sys.maxint will return positive values in Python 2.4 and up eval(c) -1

Or, without using weird functions not used from day to day, so does
this: def f(): return 0xffffffff <stdin>:1: FutureWarning: hex/oct constants > sys.maxint will return positive values in Python 2.4 and up f()

-1

Jeff

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[Terry Carroll]

On Sun, 17 Oct 2004 20:35:54 -0500, Jeff Epler <je****@unpythonic.net>
wrote:

On Sun, Oct 17, 2004 at 06:18:06PM -0700, Terry Carroll wrote:

Why won't the filterwarnings call suppress this?

The warning is produced at the time the code is *parsed*, not when it is
*executed*. You could suppress the warning in an imported module by
putting the suppression above the import of the problem module, for
instance.

Thanks!

The problem code was actually:

sum = sum & 0xffffffff

Which was unnecessary, so I removed it, but I was curious why the
suppression technique, my first cut at fixing it (just in case I
misunderstood something) didn't work.