Question

I’m trying to dynamically load modules I’ve created.

Right now this works properly:

import structures.index 

But if I try the same thing by importing it dynamically, it fails.

struct = __import__('structures.index') 

Error supplied is:

Error ('No module named structures.index',) 

Any ideas why?

---

Edit: When using full scope (it sort of works?):

struct = __import__('neoform.structures.index') 

This doesn’t throw any errors, however, it isn’t loading the index module, it’s loading the ‘neoform’ module instead.

The result of ‘struct’ is:

<module 'neoform' from '/neoform/__init__.py'> 

Also, as a side question, how can I then instantiate a class within a dynamically loaded module? (assuming all the modules contain a common class name).

Edit: Solution: (thanks coonj & Rick) This ended up being what worked. Not sure why (yet), but the fromlist had to be something ‘anything apparently, since it worked when I put the letter ‘a’ as a value (strange, given that the file only had 1 class in it).

def get_struct_module(self, name):     try:         return = __import__('neoform.structures.' + name, fromlist='*')     except ImportError, e:         self.out.add('Could not load struct: neoform.structure.' + name + '\n\n' + 'Error ' + str(e.args)) 

Answer 1

I’m not sure what ‘it fails’ means, so I’ll just mention that __import__('structures.index') should, in fact, work, but it doesn’t assign the module name in the current scope. To do that (and then use a class in the dynamically imported module), you’ll have to use:

structures = __import__('structures.index') structures.index.SomeClass(...) 

The complete details on __import__ are available here.

Edit: (based on question edit)

To import neoform.structures.index, and return the index module, you would do the following:

structures = __import__('neoform.structures.index',                          fromlist=['does not in fact matter what goes here!']) 

So if you have a list of package names packages, you can import their index modules and instantiate some MyClass class for each using the following code:

modules = [ __import__('neoform.%s.index' % pkg, fromlist=['a'])              for pkg in packages ] objects = [ m.MyClass() for m in modules ]