Question

我有：

new_dict['a1']['Road_Type']=[0,0,0,0,0,0,0]
new_dict['a2']['Road_Type']=[0,0,0,0,0,0,0]
new_dict['a3']['Road_Type']=[0,0,0,0,0,0,0]
new_dict['a4']['Road_Type']=[0,0,0,0,0,0,0]

现在更新后我希望它是：

new_dict['a1']['Road_Type']=[0,0,0,0,0,0,0]
new_dict['a2']['Road_Type']=[5,0,0,0,0,0,0]
new_dict['a3']['Road_Type']=[0,0,0,0,0,0,0]
new_dict['a4']['Road_Type']=[0,0,0,0,0,0,0]

我的代码：

kk=new_dict['a2']['Road_Type']
kk[0]=5
new_dict['a2']['Road_Type']=kk

但结果是：

new_dict['a1']['Road_Type']=[5,0,0,0,0,0,0]
new_dict['a2']['Road_Type']=[5,0,0,0,0,0,0]
new_dict['a3']['Road_Type']=[5,0,0,0,0,0,0]
new_dict['a4']['Road_Type']=[5,0,0,0,0,0,0]

所有值都在更新，因此如何更新特定值。

Answer 1

只需单独更新a2：

new_dict = {
    'a1': {'Road_Type': [0,0,0,0,0,0,0]},
    'a2': {'Road_Type': [0,0,0,0,0,0,0]},
    'a3': {'Road_Type': [0,0,0,0,0,0,0]},
    'a4': {'Road_Type': [0,0,0,0,0,0,0]},
}

new_dict['a2']['Road_Type'][0] = 5

print(new_dict)

输出：

{'a1': {'Road_Type': [0, 0, 0, 0, 0, 0, 0]}, 
 'a2': {'Road_Type': [5, 0, 0, 0, 0, 0, 0]}, 
 'a3': {'Road_Type': [0, 0, 0, 0, 0, 0, 0]}, 
 'a4': {'Road_Type': [0, 0, 0, 0, 0, 0, 0]}}

Answer 2

根据您对问题的评论，由于不了解Python的工作原理，您犯了一个错误。我会在示例中简化它，但是当您拥有new_dict[a][b]...[n]时，这也代表了您的情况。

以下是您生成词典的方法：

lst = [0, 0, 0, 0, 0, 0, 0]
new_dict = []
for p in range(N):
    new_dict[p] = lst

然而，这会将new_dict[p]的每个p=0,...,N绑定到相同的lst，即每个new_dict[p]值引用list的相同实例。

您必须为每个new_dict[p]生成新列表。

以下是如何生成它：

new_dict = {}

for p in range(N):
    new_dict[p] = [0, 0, 0, 0, 0, 0, 0]

填充词典后，您可以用一行编辑它：

new_dict['a1']['RoadType'][0] = 5

Answer 3

试试这段代码：您的代码中存在一个小错误，您更新'a2'的索引0然后指定指向'a2'的new_dict的'kk'

计划：

new_dict = {}
new_dict['a1']= {'Road_Type': [0,0,0,0,0,0,0]}
new_dict['a2']= {'Road_Type': [0,0,0,0,0,0,0]}
new_dict['a3']= {'Road_Type': [0,0,0,0,0,0,0]}
new_dict['a4']= {'Road_Type': [0,0,0,0,0,0,0]}


kk=new_dict['a2']['Road_Type']
kk[0]=5

print(new_dict)

输出

{'a2': {'Road_Type': [5, 0, 0, 0, 0, 0, 0]}, 
 'a3': {'Road_Type': [0, 0, 0, 0, 0, 0, 0]},
 'a4': {'Road_Type': [0, 0, 0, 0, 0, 0, 0]},
 'a1': {'Road_Type': [0, 0, 0, 0, 0, 0, 0]}}

如何使用python

3 个答案: