def read_tles(tle_path):
    """
    Convert TLE text files in a given directory to a list of TLEs.

    Parameters
    ----------
    tle_dir : str
        Path to the directory containing TLE .txt files.

    Returns
    -------
    sats : List of lists.
        Each internal list has the 3 lines of a TLE as its elements.
    """

    tles = [line.rstrip() for line in open(tle_path)]
    sats = [tles[3*i:(3*i+3)] for i in range(len(tles)//3)]

    return sats