关于python：字典使用问题


Dictionary use problems

本问题已经有最佳答案，请猛点这里访问。

这是我的代码：

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everyday = {'hello':[],'goodbye':{}}
i_want = everyday
i_want ['afternoon'] = 'sun'
i_want['hello'].append((1,2,3,4))
print(everyday)

我想获得：

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i_want = {'afternoon': 'sun', 'hello': [(1, 2, 3, 4)], 'goodbye': {}}

everyday = {'hello':[],'goodbye':{}}

号

但我得到：

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i_want = {'afternoon': 'sun', 'hello': [(1, 2, 3, 4)], 'goodbye': {}}

everyday = {'afternoon': 'sun', 'hello': [(1, 2, 3, 4)], 'goodbye': {}}

在不修改"日常"字典的情况下，我怎么能得到我想要的？

相关讨论

只需更改：

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everyday = {'hello':[],'goodbye':{}}
i_want = dict(everyday)
i_want ['afternoon'] = 'sun'
i_want['hello'] = []    # We're facing the same issue here and this is why we are initializing a new list and giving it to the hello key
i_want['hello'].append((1,2,3,4))

# to add to goodbye don't forget  the following:
# i_want['goodbye'] = {}
# i_want['goodbye'] ="Some value"

print(everyday)

现在的情况是，打电话(我想=每天)实际上是在创建对每天的引用

为了进一步测试，如果您想查看您的字典是否被引用，只需调用

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print(i_want is everyday)

号

下面的工作类似于Marc的答案，但您不需要创建一个新的列表，然后添加，而是在创建列表的同时进行。

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everyday = {'hello':[],'goodbye':{}}
print("everyday:", everyday)
i_want = dict(everyday)
i_want ['afternoon'] = 'sun'
i_want['hello'] = [(1, 2, 3, 4)]
print("everyday:", everyday)
print("i_want:", i_want)

输出：

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everyday: {'hello': [], 'goodbye': {}}
everyday: {'hello': [], 'goodbye': {}}
i_want: {'hello': [(1, 2, 3, 4)], 'goodbye': {}, 'afternoon': 'sun'}

。

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everyday = {'hello':[],'goodbye':{}}
print ('Everyday:',everyday)
i_want = everyday
i_want ['afternoon'] = 'sun' i_want['hello'].append((1,2,3,4))
print(everyday)

只需添加第二个print语句即可获得所需的输出。