例子1：
In [17]: nums = range(10)
In [18]: nums_temp = nums
In [20]: nums_temp[0] = "comk"
In [21]: nums
Out[21]: ['comk', 1, 2, 3, 4, 5, 6, 7, 8, 9]
In [22]: nums_temp
Out[22]: ['comk', 1, 2, 3, 4, 5, 6, 7, 8, 9]
例子2：
In [23]: nums = range(10)
In [25]: nums_temp = nums[:]
In [26]: nums_temp[0] = "comk"
In [27]: nums
Out[27]: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
In [28]: nums_temp
Out[28]: ['comk', 1, 2, 3, 4, 5, 6, 7, 8, 9]