how to import a name from a module-path?

[thebjorn]

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

 

[Gary Herron]

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

 

[thebjorn]

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