用例子说明。
fruit = ['pineapple','grape','pear']
fruit[0:0] = ['Orange'] #在fruit集合中第一位插入字符串'Orange'
print(fruit) #['Orange','pineapple','grape','pear']
fruit[0] = 'Grapefruit' #将fruit集合的第一位元素替换为'Grapefruit'
print(fruit) #['Grapefruit','pineapple','grape','pear']
fruit[0:0] = 'Grapefruit'
print(fruit) #['G','r','a','p','e','f','r','u','i','t','Grapefruit','pineapple','grape','pear']