import and function question

[Alex Martelli]

Moray Taylor wrote:

> Hi,
> 
> I have two questions..
> 
> a) Can I 'import' a module with the full path, i.e. I don't want to
> add it to sys.path, just something like 'import /home/me/mod.py', is
> this possible.
> I have tried adding it to the path, importing, and immediatly removing
> it from the path, but the next time I do an 'import' with a different
> module of the same name, it picks up the old one, even though it isn't
> in the sys.path.

The import statement will always pick up sys.modules[name] when you
import name.  If that's not what you need (and for plugins you may
not want that, indeed) see the imp module in the standard library.
imp.find_module lets you find a module on a directory-path of your
choice, then imp.load_module lets you load the module you've found.

> b) I need to overwrite a function with a new one of the same name, but
> 'import'ed from a module. Is this possible, I really just need to
> destroy this function before I import the new one, can this be done?

del thefunctionname

will unbind the name from the function object ("destroy" only if there
are no other references -- you cannot destroy an object to which there
are outstanding references, Python saves you from dangling reference
problems; if you have subtle needs e.g. for caching, see the weak
references module).  Most often, though, just:

thefunctionname = themodulename.thefunctionname

(after importing the module and binding the module object to name
themodulename -- whether by an import statement or by more devious
means) will suffice.


Alex