在python中复制列表 [英] copy list in python

问题描述

我正在尝试制作列表的副本，并使用列表的副本做一些事情.不知何故，我的原始列表也被修改了.我已经研究过不同的内存分配方式和分配列表的不同方式.到目前为止没有运气...有什么想法吗?

As I am trying to make a copy of a list and do some stuff with the copy of the list. Somehow my original list is modified as well. I already looked at different memory allocatinos and different ways of assigning the lists. So far no luck... Any ideas?

    row = 0
    column = 0
    table1 = copy.copy(table[:])

    temptable = []
    temptable = table[:]

    print id(table)
    print table
    print id(table1)
    print table1
    print id(temptable)
    print temptable

    for i in temptable:
        for j in i:
            if type(j) == str:
                temptable[row][column] = 0
            column = column + 1
        column = 0
        row = row + 1
    result=[]   

    for column in zip(*temptable):
        try:
                result.append(sum(map(int,column)))
            except ValueError:
                result.append(0)


    print table
    print table1
    print temptable

/####结果

163783148
[[0, 'ZZZ', 'XXX', 'YYY', 'AAA', 0, 0], ['BBB', 1, 1, 0, 26, 28, 0], ['CCC', 26, 0, 0, 0, 26, 0], ['DDD', 0, 26, 0, 0, 26, 0], ['EEE', 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0]]

163669036
[[0, 'ZZZ', 'XXX', 'YYY', 'AAA', 0, 0], ['BBB', 1, 1, 0, 26, 28, 0], ['CCC', 26, 0, 0, 0, 26, 0], ['DDD', 0, 26, 0, 0, 26, 0], ['EEE', 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0]]

163783468
[[0, 'ZZZ', 'XXX', 'YYY', 'AAA', 0, 0], ['BBB', 1, 1, 0, 26, 28, 0], ['CCC', 26, 0, 0, 0, 26, 0], ['DDD', 0, 26, 0, 0, 26, 0], ['EEE', 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0]]

[[0, 0, 0, 0, 0, 0, 0], [0, 1, 1, 0, 26, 28, 0], [0, 26, 0, 0, 0, 26, 0], [0, 0, 26, 0, 0, 26, 0], [0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0]]

[[0, 0, 0, 0, 0, 0, 0], [0, 1, 1, 0, 26, 28, 0], [0, 26, 0, 0, 0, 26, 0], [0, 0, 26, 0, 0, 26, 0], [0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0]]

[[0, 0, 0, 0, 0, 0, 0], [0, 1, 1, 0, 26, 28, 0], [0, 26, 0, 0, 0, 26, 0], [0, 0, 26, 0, 0, 26, 0], [0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0]]

推荐答案

您的原始列表包含内部列表:

Your original list contains inner lists:

[[0, 'ZZZ', 'XXX', 'YYY', 'AAA', 0, 0], 
 ['BBB', 1, 1, 0, 26, 28, 0], ...
]

内部列表实际上存储为引用，即:

The inner list are actually stored as references, i.e.:

[ location-of-list-0, 
  location-of-list-1, ...
]

复制列表时，实际上是将引用列表复制到原始列表中存储的相同列表中.这称为浅表复制，因为它复制引用而不是内容.

When you copied the list, you actually copied a list of references to the same lists stored in your original list. This is called shallow copy, as it copies references rather than contents.

使用深度复制创建一个完全独立的列表.

Use deep copy to create a totally separate list.

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