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I'm storing the path to functions in a database and now I'd like to
get a reference so I can execute them.

I looked briefly at the imp module and got very confused... Currently
I'm doing this:

def import_object(path):
module, obj = path.rsplit('.', 1)
exec "from rootpkg.%s import %s as fn" % (module, obj)
return fn

function = import_object('mypackage.mymodule.myfunction')

this is happening in a trusted environment, so I'm not worried about
malicious code.

Are there more elegant ways of doing this (ie. without exec)?

-- bjorn

thebjorn wrote:
> I'm storing the path to functions in a database and now I'd like to
> get a reference so I can execute them.
>
> I looked briefly at the imp module and got very confused... Currently
> I'm doing this:
>
> def import_object(path):
> module, obj = path.rsplit('.', 1)
> exec "from rootpkg.%s import %s as fn" % (module, obj)
> return fn
>
> function = import_object('mypackage.mymodule.myfunction')
>
> this is happening in a trusted environment, so I'm not worried about
> malicious code.
>
> Are there more elegant ways of doing this (ie. without exec)?
>

Yes. Look at the __import__ builtin function, and if that's not enough
functionality, look at the module names imp, which provides
documentation starting with this bit:

DESCRIPTION
This module provides the components needed to build your own
__import__ function.



Both are available in Python2.x and Python3.x

Gary Herron



> -- bjorn
>

On Jun 16, 7:43*pm, Gary Herron <gher...@islandtraining.com> wrote:
> thebjorn wrote:
> > I'm storing the path to functions in a database and now I'd like to
> > get a reference so I can execute them.
>
> > I looked briefly at the imp module and got very confused... *Currently
> > I'm doing this:
>
> > * def import_object(path):
> > * * * module, obj = path.rsplit('.', 1)
> > * * * exec "from rootpkg.%s import %s as fn" % (module, obj)
> > * * * return fn
>
> > * function = import_object('mypackage.mymodule.myfunction')
>
> > this is happening in a trusted environment, so I'm not worried about
> > malicious code.
>
> > Are there more elegant ways of doing this (ie. without exec)?
>
> Yes. *Look at the __import__ builtin function,
[...]

Thanks, that is much better:

def import_object(path):
module, obj = path.rsplit('.', 1)
m = __import__(module, fromlist=['rootpkg'])
return getattr(m, obj)

function = import_object('mypackage.mymodule.myfunction')


> Gary Herron

Bjorn