[SciPy-dev] Advice on numpy/scipy namespace issue (ipython etc.)

Tom Loredo loredo at astro.cornell.edu
Sun Jan 8 14:18:03 CST 2006


Hi folks,

Okay, as one who complained about the lack of numpy top-level
objects in scipy's top-level namespace, I'm pursuaded by Travis
and Pearu that a separation should be seriously considered, and
that now is the time.  I'd like some advice about handling
the namespace split properly.

I know that "from ... import *" is bad behavior, but particularly
for interactive use it's sometimes irresistable.  If I do

from numpy import *
from scipy import *

is there any namespace collision I should be aware of?  Are
there any scipy modules or top-level functions with the same
name as numpy's (or vice versa)?  Both packages have "fft"
at the top level, for example.

"ipython -p scipy" imports top-level scipy into its namespace, but not
top-level numpy.  This doesn't seem right to me---surely one will be
using array and zeros more often than fftpack---but the "import *"
issue has to be settled if we want "-p scipy" to have all the
handy numpy stuff at its top level.

As a more specific example, what exactly is the difference
between numpy.fft and scipy.fft?

As a quick exploration of the issue, I ran this:

import numpy, scipy

nall = numpy.__all__

for name in scipy.__all__:
	if name in nall: print name

The result was only 3 names:  lib, fft, ifft.  lib in particular is
quite different in scipy vs. numpy.  If the common name is kept,
perhaps some convention should be recommended for * use, as in ipython,
so users can count on lib meaning the same thing at an interactive
prompt.  It would probably be better to rename one of the libs (e.g.,
"mlib" for scipy's since it's a matrix library, vs. numpy's more
general-purpose lib), but I suppose it's late for that.  I don't know
if the fft name collision is an issue.

Thanks,
Tom




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