def is_vimball(fd):
    """Test for vimball archive format compliance.

    Simple check to see if the first line of the file starts with standard
    vimball archive header.
    """
    fd.seek(0)
    try:
        header = fd.readline()
    except __HOLE__:
        # binary files will raise exceptions when trying to decode raw bytes to
        # str objects in our readline() wrapper
        return False
    if re.match('^" Vimball Archiver', header) is not None:
        return True
    return False
dataset/ETHPy150Open radhermit/vimball/vimball/base.py/is_vimball