def floatToPercentString(x, decimalPlaces = 1):
    """
    Format a float as a truncated percent string.
    
    Parameters
    ----------
    x : float
        Must be between 0 and 1 to represent 0% to 100%.
    decimalPlaces : int, optional
        The number of decimal places to the right to conserve.
    
    Returns
    -------
    str
        String of `x`, shortened to `decimalPlaces` decimal places, concatenated with the '%' sign.
    """
    return ("%2." + str( decimalPlaces ) + "f") % (x * 100) + '%'