On Wed, 21 Mar 2007 00:29:00 +1100, Steven D'Aprano wrote: > On Tue, 20 Mar 2007 12:09:29 +0000, Doug Gray wrote: > >> Folks, >> I am looking for a fast but most importantly a bullet proof method to pass >> and NMEA data stream (GPS output) ascii numeric strings. The best I can >> offer is: >> >> def fint(a): >> try: return int(float(a)) >> except: return 0 > > > Will your application calculate the wrong results if it starts getting a > whole lot of spurious zeroes? Wouldn't it better to signal "this value is > invalid" rather than a false zero? > > Do you actually want ints? It seems to me that if your data stream is > delivering floats, you're throwing away a lot of data. For example, if the > data stream is: > > 2.4, 5.7, 3.9, 5.1, ... > > you're getting: > > 2, 5, 3, 5, ... > > which is possibly not even the right way to convert to ints. Shouldn't you > be rounding to nearest (i.e. 2, 6, 4, 5, ...)? > > [snip] >
Thanks, a very helpful response. I'll need some time to fully digest. Yes I will need a float variant, the int version was by way of example. I can deal with the rounding etc as necessary, but I was after an pythonistic view of the generic problem. Re the examples: whitespace and mal positioned signs and decimal point would be the obvious errors I might expect but of course this is speculation. The few GPS units I have tried have all tripped up my first cut less tolerant code. I am going to revise the interface to work around potential problems and my preliminary test efforts highlighted more exceptions than I expected. Doug -- http://mail.python.org/mailman/listinfo/python-list
