extend() 与append()的区别

attend()是延展列表，append()是将后面的当做一个元素添加至列表。

a = [1,2,3]
b = [4,5,6]
a.extend(b)
print(a)
>>>[1, 2, 3, 4, 5, 6]

a = [1,2,3]
b = [4,5,6]
a.append(b)
print(a)
>>>[1, 2, 3, [4, 5, 6]]