def _concat(prefix, list, suffix, env, f=lambda x: x, target=None, source=None):
    """
    Creates a new list from 'list' by first interpolating each element
    in the list using the 'env' dictionary and then calling f on the
    list, and finally calling _concat_ixes to concatenate 'prefix' and
    'suffix' onto each element of the list.
    """
    if not list:
        return list

    l = f(SCons.PathList.PathList(list).subst_path(env, target, source))
    if l is not None:
        list = l

    return _concat_ixes(prefix, list, suffix, env)
def _concat ( prefix , list , suffix , env , f = lambda x : x , target = None , source = None ) : if not list : return list l = f ( SCons . PathList . PathList ( list ) . subst_path ( env , target , source ) ) if l is not None : list = l return _concat_ixes ( prefix , list , suffix , env )
Creates a new list from 'list' by first interpolating each element
    in the list using the 'env' dictionary and then calling f on the
    list, and finally calling _concat_ixes to concatenate 'prefix' and
    'suffix' onto each element of the list.