[SciPy-user] fromfile, item, what other output than stdout / stderr is used ?

Robert Kern robert.kern@gmail....
Mon May 11 14:18:44 CDT 2009

On Mon, May 11, 2009 at 13:43, Christopher Barker <Chris.Barker@noaa.gov> wrote:
> Pauli Virtanen wrote:
>> Fromstring raises "ValueError: string is smaller than requested size" if
>> the string is too short to contain the requested data. Should fromfile do
>> the same,
> yes. Or some other exception.
>> or do we want to just raise a warning and return fewer items?
> maybe, but I don't like that -- you'd have to write code to catch it.
>> Or maybe only return fewer items, without a warning?
> absolutely not! Then we'd all have to write code to check the result
> every time -- yech!

There is a long history of returning what bytes you can without
raising an error. This helps a lot when writing code that reads a
chunk at a time. E.g. file.read(nbytes) will return nbytes or fewer if
you get within nbytes of the end of the file.

I suggest using the warnings mechanism. This lets you either silence
the warning or turn it into an exception depending on your use case.

Robert Kern

"I have come to believe that the whole world is an enigma, a harmless
enigma that is made terrible by our own mad attempt to interpret it as
though it had an underlying truth."
  -- Umberto Eco

More information about the SciPy-user mailing list