def walklevel(some_dir, level=1):
    """Walklevel walks through higher level dirs to a certain depth.
    Is used as an interator in loops, e.g.:
            sim_paths = []
            for path,dirs,files in walklevel('.', depth):
                  if 'start.in' in files and 'run.in' in files:
                    print '## Found Simulation in '+path
                    sim_paths.append(path)

    Args:
          some_dir:		at which dir to start the walklevel algorithm
          level:		how deep this algorithm shall walk through dirs, default is 1

    Yields:
          yield root, dirs, files
    """
    import os

    some_dir = some_dir.rstrip(os.path.sep)
    assert os.path.isdir(some_dir)
    num_sep = some_dir.count(os.path.sep)
    for root, dirs, files in os.walk(some_dir):
        yield root, dirs
        num_sep_this = root.count(os.path.sep)
        if num_sep + level <= num_sep_this:
            del dirs[:]