Duplicating Modules

[Misto .]

Hi folks!

Short:

There is a way to dumplicate a module ?

I tried
copy.deepcopy(m odule) but hangs with an error (also with standard modules )..

The only solution that I have by now is creating two files and importing them.
I.E:[color=blue]
> cp module.py module1.py[/color]
[color=blue][color=green]
>> import module
>> import module1[/color][/color]


Any Ideas?

P.S: I know that there is some design Issue here, but my boss says no :)

Misto

[kimes]

Re: Duplicating Modules

Why don't you do like this..

import module
import mudule as module2

[Peter Otten]

Re: Duplicating Modules

kimes wrote:
[color=blue]
> Why don't you do like this..
>
> import module
> import mudule as module2[/color]
[color=blue][color=green][color=darkred]
>>> import module as a
>>> import module as b
>>> b is a[/color][/color][/color]
True

You have to remove the module from the cache before the second import:
[color=blue][color=green][color=darkred]
>>> import sys
>>> import module as a
>>> del sys.modules["module"]
>>> import module as b
>>> b is a[/color][/color][/color]
False

Peter

[Dave Benjamin]

Re: Duplicating Modules

Misto . wrote:[color=blue]
> Hi folks!
>
> Short:
>
> There is a way to dumplicate a module ?[/color]

Here's one way... it doesn't quite work with modules inside of packages,
unfortunately, but it does avoid defeating module caching and tries to
keep sys.modules in a predictable state. I don't know what the
thread-safety implications are for this sort of trickery with sys.modules.

def import_as(newna me, oldname):
"""Import a module under a different name.

This procedure always returns a brand new module, even if
the original module has always been imported.

Example::

try:
# Reuse this module if it's already been imported
# as "mymath".
import mymath
except ImportError:
# "mymath" has not yet been imported.
# Import and customize it.
mymath = import_as('myma th', 'math')
mymath.phi = (mymath.sqrt(5. 0) - 1.0) / 2.0

The above code will not reinitialize "mymath" if it executes
a second time (ie. if the module containing this code is
reloaded). Whether or not "math" has already been imported,
it will always be a different object than "mymath".
"""

import sys
if sys.modules.has _key(oldname):
tmp = sys.modules[oldname]
del sys.modules[oldname]
result = __import__(oldn ame)
sys.modules[newname] = sys.modules[oldname]
sys.modules[oldname] = tmp
else:
result = __import__(oldn ame)
sys.modules[newname] = sys.modules[oldname]
del sys.modules[oldname]
return result

Dave

[Steven D'Aprano]

Re: Duplicating Modules

On Fri, 30 Sep 2005 19:52:56 +0200, Misto . wrote:
[color=blue]
> There is a way to dumplicate a module ?[/color]

[snip]
[color=blue]
> P.S: I know that there is some design Issue here, but my boss says no :)[/color]

It depends on what you are expecting to do with the duplicated module. If
all you need is to access the same module from two different names, you
can do this:

py> import sys
py> my_boss_is_an_i diot = sys # *grins*
py> my_boss_is_an_i diot.version
'2.3.3 (#1, May 7 2004, 10:31:40) \n[GCC 3.3.3 20040412 (Red Hat Linux
3.3.3-7)]'


But keep in mind that using this method, sys and my_boss_is_an_i diot are
merely different names for the same underlying module. Change one and you
change the other.

I'm curious... I don't expect you to comment on your boss' mental state,
but how/why do you need to duplicate the module?


--
Steven.