def read_psd(psd_file, df):
    """Read in a psd file

    Parameters
    ----------
    strain: dict
        dictionary containing the psds for each detector
    df: float
        df to use when reading in the psd_file

    Returns
    -------
    psd_data: pycbc.frequencyseries.FrequencySeries
        data stored in the psd file
    """
    from pycbc.psd.read import from_txt
    return from_txt(psd_file, int(1024.0 / df) + 1, df, 20, is_asd_file=False)
