+def submods(this_modname, submodnames):
+ """Iterate through (submodname, submod) pairs.
+ """
+ for submodname in submodnames:
+ count = len([s for s in submodnames if s == submodname])
+ assert count > 0, 'No %s entries: %s' % (submodname, submodnames)
+ assert count == 1, 'Multiple (%d) %s entries: %s' \
+ % (count, submodname, submodnames)
+ this_mod = __import__(this_modname, fromlist=[submodname])
+ submod = getattr(this_mod, submodname)
+ yield (submodname, submod)
+
+