On 12/22/2009 12:06 PM, W. eWatson wrote:
Stephen Hansen wrote:
On Mon, Dec 21, 2009 at 2:57 PM, W. eWatson <wolftra...@invalid.com>
wrote:
[snip
Now, I go to the script and enter
from math import *
dir is now bulked up with the math functions. I change back math.cos
to cos
and the program runs well.
This sort of figures. Apparently, I've added to the namespace by
importing
with *.
Apparently? -- you precisely and explicitly added every object in
'math' to your current namespace. "from math import *" does precisely
that.
Well, it's a big surprise to me, because I thought each time I ran from
the editor that it reloaded the modules in my imports, and cleared out
any it didn't find.
>
My point is that I'm betting different results. OK, fine. It appears the
same thing happens with I modify the program itself with from math
import *
Different results? What different results are you talking about?
>
It seems to me as I fool around with interpreter under the script
window, I"m creating a mess out of the namespace the program uses, and
the program responds incorrectly.
After a script's execution, IDLE's shell namespace uses the last
scripts's namespace; this is similar to using the -i switch in the terminal:
$ python -i myscript.py
program output
>>> foo() # foo() is a function defined in myscript.py
this is often useful for debugging
If you want to access 'sin' without 'math.', you'll have to do 'from
math import *' in each file where you want to do that.
So IDLE is not clearing the namespace each time I *run* the program.
This is
not good. I've been fooled. So how do I either clear the namespace
before
each Run? Do I have to open the file in the editor again each time
before
trying to Run it? I hope there's a better way.
How do you figure its 'not clearing the namespace'? In which
namespace? I fire up IDLE, and start a new file, and put in a single
Try this sequence.
I just started plugging away again with IDLE and am pretty convinced
that IDLE is something of an enemy. I started afresh loading this into
the editor:
import math
print "hello, math world."
print math.cos(0.5)
print math.sin(0.8)
Run works fine. No errors. Now I do:
>>> dir()
['__builtins__', '__doc__', '__file__', '__name__', 'idlelib', 'math']
>>>
OK, swell. Now I import via the script window
>>> import numpy as np
>>> dir()
['__builtins__', '__doc__', '__file__', '__name__', 'idlelib', 'math',
'np']
I think I'm adding to the namespace, both the program the shell sees,
because adding this ref to np in the program works fine.
import math
print "hello, math world."
print math.cos(0.5)
print math.sin(0.8)
print np.sin(2.2) <<<<-------
There's no np in that code, but yet it works. It must be in the
namespace it sees, and it was put there through the interactive shell.
You must be starting IDLE without subprocess. Did you see this message
IDLE 2.6.1 ==== No Subprocess ====
when starting IDLE.
If you're on Windows, don't use the "Edit with IDLE" right-click hotkey
since that starts IDLE without subprocess. Use the shortcut installed in
your Start menu.
line: "a = 1". I choose Run Module, and it runs it. I verify in the
interactive interpreter that a is 1. I then change that file to "a = a
+ 1", and run it. Now, it errors out-- of course-- because IDLE
"cleared" the namespace and re-ran the module.
Hmmm, that appears to contrary to my numpy experience. I've never seen
any re-starting msg.
Python 2.5.2 (r252:60911, Feb 21 2008, 13:11:45) [MSC v.1310 32 bit
(Intel)] on win32
Type "copyright", "credits" or "license()" for more information.
That is irrelevant with numpy. If you start IDLE with subprocess, then
every time before you run a script this message appears:
>>> ============================= RESTART =============================
PS: you can force IDLE to restart the subprocess with Ctrl+F6
It says in the interpreter its restarting, even.
When IDLE is not run with subprocess, running a script is equivalent to
copy and pasteing the script to the shell.
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