def set_defaults(hotpotato):
    """
    Set default values for keys in a dictionary of input parameters.

    Parameters
    ----------
    hotpotato : dictionary
         Dictionary of input parameters gathered from a configuration script

    Returns
    -------
    hotpotato : dictionary
        Input dictionary with keys set to default values
    """
    if hotpotato['inject_channels']=='':
        hotpotato['inject_channels'] = []
    if hotpotato['periods']=='':
        hotpotato['periods'] = []
    if hotpotato['duty_cycles']=='':
        hotpotato['duty_cycles'] = []
    if hotpotato['pulse_SNR']=='':
        hotpotato['pulse_SNR'] = []
    if hotpotato['initial_phase']=='':
        hotpotato['initial_phase'] = []
    if hotpotato['source_name']=='':
        hotpotato['source_name'] = 'Unknown'
    if hotpotato['tstart']=='':
        hotpotato['tstart'] = 0.0
    return hotpotato