如何用0赋值dataframe的主对角线和副对角线？

df = pd.DataFrame(np.random.randint(1,100, 25).reshape(5, -1))
print(df)
# zhu
for i in range(df.shape[0]):
    df.iat[i, i] = 0
    df.iat[df.shape[0]-i-1, i] = 0
print(df)

#>	    0   1   2   3   4
	0  51  35  71  71  79
	1  78  25  71  85  44
	2  90  97  72  14   4
	3  27  91  37  25  48
	4   1  26  68  70  20

#>	    0   1   2   3   4
	0   0  35  71  71   0
	1  78   0  71   0  44
	2  90  97   0  14   4
	3  27   0  37   0  48
	4   0  26  68  70   0