def count_placeholders(peaks):
    """Counts the number of placeholder peaks in an iterable
    of FittedPeaks

    Parameters
    ----------
    peaks : Iterable of FittedPeak

    Returns
    -------
    int
        Number of placeholder peaks
    """
    i = 0
    for peak in peaks:
        if peak.intensity <= 1:
            i += 1
    return i