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我正在使用 Python 3.4。
我注意到这种奇怪的行为:
In [1]: a=[1,2,3,4,5,6,7,8,9]
In [2]: b=[10,11,12,13,14,15,16,17,18,19]
In [3]: type(a)
Out[3]: list
In [4]: a
Out[4]: [1, 2, 3, 4, 5, 6, 7, 8, 9]
In [5]: b
Out[5]: [10, 11, 12, 13, 14, 15, 16, 17, 18, 19]
In [6]: c=a
In [7]: c
Out[7]: [1, 2, 3, 4, 5, 6, 7, 8, 9]
In [8]: c.extend(b)
In [9]: c
Out[9]: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]
In [10]: a
Out[10]: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]
c上的extend方法为什么修改了a？
您观察到相同的行为吗？
正常吗？在这种情况下，我如何扩展 c 而使 a 完好无损？