Testing for presence of arguments

[Madhusudan Singh]

Hi

I know how to set optional arguments in the function definition. Is there an
intrinsic function that determines if a certain argument was actually
passed ? Like the fortran 95 present() logical intrinsic ?

My required functionality depends on whether a certain argument is specified
at all. (Setting default values is *not* good enough.).

Thanks.

[Madhusudan Singh]

Diez B. Roggisch wrote:

I still don't see why default arguments like None won't do the trick.
If The argument _can_
be some value (let's say an int) or None, you still could go for a
default value like () or any other value
from a different domain.

"None" works perfectly. Someone else on the thread suggested it. I did not
know about the special intrinsic.

Unrelated question, how does one call a fortran 95 subroutine from python
? I need really high speed of execution for that call (needed for each
measurement point, and is used to calculate some parameters for the
excitation for the next measurement point) and a scripting language would
not cut it.

Didn't ever try that, but either do it in C, or if fortran code can be
exposed as C lib, use that (ctypes is your friend). I'm not aware of a
fortran binding - but I never tried to find one. Basically Python can
interface with everything that can behave like C - which is the least
common denominator I think, so there should be some way.

Hmm. Thanks for the pointers here.

[Robert Kern]

Madhusudan Singh wrote:

Unrelated question, how does one call a fortran 95 subroutine from python ?
I need really high speed of execution for that call (needed for each
measurement point, and is used to calculate some parameters for the
excitation for the next measurement point) and a scripting language would
not cut it.

http://cens.ioc.ee/projects/f2py2e/

--
Robert Kern
rk***@ucsd.edu

"In the fields of hell where the grass grows high
Are the graves of dreams allowed to die."
-- Richard Harter

[Peter Maas]

Madhusudan Singh schrieb:

Dan Sommers wrote: [...]

class _SemiPrivateCla ss:
pass

def f(required_argu ment=_SemiPriva teClass):
if required_argume nt == _SemiPrivateCla ss:
print "required_argum ent was probably not present"
else:
print "required_argum ent was present"

[...] Thanks for the suggestion, but seems needlessly complicated for
something very simple.

What is "very simple"? The problem or the solution? :) If you examine
this suggestion more closely you will note that it is more or less
the same as Benji York's one except Benji used a built-in class.

If you are interested in getting help on usenet you should abstain
from devaluating efforts to give you a useful reply. "Thanks for
the suggestion" or even no answer would have been sufficient.

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[Madhusudan Singh]

Peter Maas wrote:

Thanks for the suggestion, but seems needlessly complicated for
> something very simple.
What is "very simple"? The problem or the solution? :) If you examine

The form of the solution.
this suggestion more closely you will note that it is more or less
the same as Benji York's one except Benji used a built-in class.
Many good solutions have some similarity. From the point of view of a user
trying to include some simple functionality in a already complicated
application, Benji's answer was most definitely more useful.

If you are interested in getting help on usenet you should abstain
from devaluating efforts to give you a useful reply. "Thanks for
the suggestion" or even no answer would have been sufficient.

One might have thought that a truthful assessment would have been
appreciated at the other end. I myself help people on the Usenet on some
other newsgroups, and am usually welcoming of responses that offer a
relevant criticism. The exchange improves me as much as it improves them.

Thanks for the suggestion, anyways :)