En Thu, 11 Sep 2008 10:43:08 -0300, john <[EMAIL PROTECTED]> escribió:
I wrapped some fortran code using F2PY and need to be able to catch
fortran runtime errors to run the following:
[reindented]
# "grid" is a wrapped fortran module
# no runtime errors incurred when run with the correct inputs for
filetype
#-------------------------------
def readGrid( self, coord='xyz' ):
mg = ( '.FALSE.', '.TRUE.' )
form = ( 'FORMATTED', 'UNFORMATTED' )
success = False
for m in mg:
for f in form:
try:
if coord == 'xyz':
self.grid.readxyz( self.filename, f, m )
success = True
elif coord == 'xyrb':
self.grid.readxyrb( self.filename, f, m )
success = True
else:
import sys
print 'gridtype "' + str(coord) + '" not supported. ' \
+ '<IO.Plot3d.Plot3d.read>'
except:
continue
if not success:
import sys
print 'gridfile "' + str(self.filename) + '" not read in any
recognized format' \
+ ' <IO.Plot3d.Plot3d.read>'
#----------------------------
I suppose you want to stop trying other formats after a successful read;
in that case put a break statement just below both success=True.
If coord is unrecognized, the code above prints the same message 4 times.
Instead of printing a message, in those cases usually an exception is
raised, letting a higher layer handle the error. And using string
interpolation is a lot easier than building the message in parts:
raise ValueError('gridtype "%s" not supported. <IO.Plot3d.Plot3d.read>' %
coord)
If you want to catch errors on the Fortran code *only*, the try/except
should be more specific (both in scope and what it catches). The Exception
class is the more generic exception that you should catch.
basically, what i want to happen is to try to run 'something' with the
wrapped fortran code and if that doesn't work (error encountered,
etc.) try something else. is there an easier way to go about doing
this? is there something i'm missing about catching exceptions here?
I'd reorder the code in this way (untested, of course):
def readGrid(self, coord='xyz'):
def try_all_formats(read_function, filename):
mg = ('.FALSE.', '.TRUE.')
form = ('FORMATTED', 'UNFORMATTED')
success = False
for m in mg:
for f in form:
try:
read_function(filename, f, m)
success = True
break
except Exception, e:
# this line only for debugging purposes
print "error %r when using m=%r f=%r" % (e, m, f)
continue
if not success:
raise ValueError('gridfile "%s" not read '
'in any recognized format '
'<IO.Plot3d.Plot3d.read>' % filename)
if coord == 'xyz':
try_all_formats(self.grid.readxyz, self.filename)
elif coord == 'xyrb':
try_all_formats(self.grid.readxyrb, self.filename)
else:
raise ValueError('gridtype "%s" not supported. '
'<IO.Plot3d.Plot3d.read>' % coord)
I don't know about F2PY but the values ('.FALSE.', '.TRUE.') seem
suspicious. AFAIR, .FALSE. and .TRUE. are the Fortran spellings of False
and True in Python - they're not strings, but boolean values. So maybe the
right way is to use
mg = (False, True)
Your code above was catching and ignoring everything, even this error, if
it happened.
--
Gabriel Genellina
--
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