code: def load_collectors_from_paths(paths):
      
      # Initialize return value
      collectors = {}
  
      if paths is None:
          return
  
      if isinstance(paths, basestring):
          paths = paths.split(',')
          paths = map(str.strip, paths)
  
      load_include_path(paths)
  
      for path in paths:
          # Get a list of files in the directory, if the directory exists
          if not os.path.exists(path):
              raise OSError("Directory does not exist: %s" % path)
  
          if path.endswith('tests') or path.endswith('fixtures'):
              return collectors
  
          # Load all the files in path
          for f in os.listdir(path):
  
              # Are we a directory? If so process down the tree
              fpath = os.path.join(path, f)
              if os.path.isdir(fpath):
                  subcollectors = load_collectors_from_paths([fpath])
                  for key in subcollectors:
                      collectors[key] = subcollectors[key]
  
              # Ignore anything that isn't a .py file
              elif (os.path.isfile(fpath) and
                    len(f) > 3 and
                    f[-3:] == '.py' and
                    f[0:4] != 'test' and
                    f[0] != '.'):
  
                  modname = f[:-3]
  
                  fp, pathname, description = imp.find_module(modname, [path])
  
                  try:
                      # Import the module
                      mod = imp.load_module(modname, fp, pathname, description)
                  except (KeyboardInterrupt, SystemExit) as err:
                      logger.error(
                          "System or keyboard interrupt "
                          "while loading module %s"
                          % modname)
                      if isinstance(err, SystemExit):
                          sys.exit(err.code)
                      raise KeyboardInterrupt
                  except Exception:
                      # Log error
                      logger.error("Failed to import module: %s. %s",
                                   modname,
                                   traceback.format_exc())
                  else:
                      for name, cls in get_collectors_from_module(mod):
                          collectors[name] = cls
                  finally:
                      if fp:
                          fp.close()
  
      # Return Collector classes
      return collectors
docs: Scan for collectors to load from path