Lou Pecora wrote:
> In article <[EMAIL PROTECTED]>,
> Robert Kern <[EMAIL PROTECTED]> wrote:
>
>> I presume what you did was something like this:
>>
>> from matplotlib import pylab
>> [N,x] = hist(eig, 10)
>>
>> What you actually want is this:
>>
>> from matplotlib import pylab
>> [N,x] = pylab.hist(eig, 10)
>>
>> Or, if you're at the interactive prompt (but remember that it is inadvisable
>> to
>> do so in modules):
>>
>> from matplotlib.pylab import *
>> [N,x] = hist(eig, 10)
>>
>> You will probably want to review the section of the tutorial on importing
>> modules if you don't understand the differences.
>
> Is pylab part of matplotlib?
Yes.
> I always thought it was the other way
> around. I have a similar view of numpy as part of scipy.
It is not.
> Maybe I'm
> confused on the dependencies. I find it confusing in the examples
> sometimes when the "bigger" package is imported (e.g. scipy) and then a
> "subpackage" is also imported. Like this:
>
> from scipi import *
> from scipi import numpy
The latter would definitely be bad form if it worked. numpy is a package all by
itself and should be imported by itself.
> I know I've seen stuff like that, but I don't get it. The dependencies
> are confusing to me.
pylab is a module provided with matplotlib that exposes a nice interface for
certain purposes. Somewhat confusingly, it is provided in two places, as its
own
module:
import pylab
and as a submodule in the matplotlib package:
from matplotlib import pylab
Both do the same thing. You get to ask John Hunter if you want to know the whys
and wherefores.
numpy is a package all by itself. scipy is a package all by itself although it
depends on numpy being installed. You cannot import numpy from scipy. The
dependency of scipy on numpy does *not* entail that scipy will provide numpy in
its namespace.
Sometimes packages/modules are sloppy and accidentally expose the modules that
they import. For example, if you had a module foo.py like this:
import bar
def dostuff():
pass
then foo.py depends on bar.py. One *could* also do this:
from foo import bar
However, as I said, this would be bad form. It is an accident that the bar
module is exposed there. It should not be imported from the foo module.
Naturally, there are exceptions. Sometimes some other module is deliberately
imported and intended to be exposed in that place. Hopefully, there is a
comment
to that effect explaining that it was intentional.
> I did a search of the tutorial on 'import' but didn't find the answer.
It certainly doesn't answer your questions, but it should answer the OP's if my
presumptions are correct. Importing a module like so:
import mymodule
from mypackage import myothermodule
does not take all of symbols in mymodule and myothermodule and place them in
the
current namespace.
http://docs.python.org/tut/node8.html
--
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
--
http://mail.python.org/mailman/listinfo/python-list
