输入符号，宽，高，打印此符号组成的矩形

def boxPrint(symbol, width, height):
    if len(symbol) != 1:
        raise Exception('Symbol（符号） must be a single character string.')
    if width <= 2:
        raise Exception('Width must be greater than 2.')
    if height <= 2:
        raise Exception('Height must be greater than 2.')
    print(symbol * width)
    for i in range(height - 2):
        print(symbol + (' ' * (width - 2)) + symbol)
    print(symbol * width)
    
for sym, w, h in (('*', 4, 4), ('O', 5, 5), ('x', 1, 3), ('ZZ', 3, 3)):
    try:
        boxPrint(sym, w, h)
    except Exception as err:
        print('An exception happened: ' + str(err))

'''输出：
****
*  *
*  *
****
OOOOO
O   O
O   O
O   O
OOOOO
An exception happened: Width must be greater than 2.
An exception happened: Symbol must be a single character string.