切片与赋值的区别

n1 = [1,2,3,4,5]

n2 = n1

n3 = n1[:]

n1[0] = 33

n3[1] = 999

print(n1)

print(n2)

print(n3)

正确答案是:

n1 = [33,2,3,4,5]

n2=[33,2,3,4,5]

n3 = [1,999,3,4,5]

解释: n2=n1赋值的时候n2和n1指向同一块地址,n1改变了,n2也跟着改变

n3 = n1[:]切片操作,又开辟了新的内存空间,指向的是新的,所以n1变化,n3不变