import __builtin__
from os import listdir
import re

files = listdir('.')

def import_problem(n, ident, *idents_opt):
    """
    import_problem(int, string[, string[, ...]]) -> (object, ...) | object
    
    Import functions/variables/objects used in the solution to a particular
    problem. This is quite hack but oh well, it makes it much easier to 
    reference and use functions from other problems.
    """
    
    pattern = re.compile("^(0*%d\s.*)\.py$" % int(n))
    
    # keep it ordered
    identifiers = [ident, ]
    identifiers.extend(idents_opt)
    
    # go find the file, import it, and then return either the specific object
    # or list of objects
    for file in files:
        match = pattern.match(file)
        if match:
            module =__import__(match.group(1), [], [], identifiers, -1)
            
            if len(identifiers) is 1:
                return getattr(module, ident)
            else:
                return [getattr(module, name) for name in identifiers]
    
    return None