在现有的 python 字典键上添加更多值
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Adding more values on existing python dictionary key
提问by Panchi
I am new to python and i am stuck while making a dictionary.. please help :)
我是 python 的新手，我在制作字典时被卡住了..请帮忙:)
This is what I am starting with :
这就是我的开始：
dict = {}
dict['a']={'ra':7, 'dec':8}
dict['b']={'ra':3, 'dec':5}
Everything perfect till now. I get :
到目前为止一切都很完美。我得到：
In [93]: dict
Out[93]: {'a': {'dec':8 , 'ra': 7}, 'b': {'dec': 5, 'ra': 3}}
But now, if I want to add more things to key 'a' and i do :
但是现在，如果我想向键 'a' 添加更多内容，我会这样做：
dict['a']={'dist':12}
Then it erases the previous information of 'a' and what i get now is :
然后它删除了'a'的先前信息，我现在得到的是：
In [93]: dict
Out[93]: {'a': {'dist':12}, 'b': {'dec': 5, 'ra': 3}}
What i get want to have is :
我想要的是：
In [93]: dict
Out[93]: {'a': {'dec':8 , 'ra': 7, 'dist':12}, 'b': {'dec': 5, 'ra': 3}}
Can someone please help??
有人可以帮忙吗？？
采纳答案by alecxe
>>> d = {}
>>> d['a'] = {'ra':7, 'dec':8}
>>> d['b'] = {'ra':3, 'dec':5}
>>> d['a']['dist'] = 12
>>> d
{'a': {'dec': 8, 'dist': 12, 'ra': 7}, 'b': {'dec': 5, 'ra': 3}}
If you want to update dictionary from another dictionary, use update():
Update the dictionary with the key/value pairs from other, overwriting existing keys.
使用其他键/值对更新字典，覆盖现有键。
>>> d = {}
>>> d['a'] = {'ra':7, 'dec':8}
>>> d['b'] = {'ra':3, 'dec':5}
>>> d['a'].update({'dist': 12})
>>> d
{'a': {'dec': 8, 'dist': 12, 'ra': 7}, 'b': {'dec': 5, 'ra': 3}}
Also, don't use dictas a variable name - it shadows built-in dicttype. See what can possibly happen:
另外，不要dict用作变量名 - 它会影响内置dict类型。看看可能会发生什么：
>>> dict(one=1)
{'one': 1}
>>> dict = {}
>>> dict(one=1)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'dict' object is not callable
回答by Panchi
Do this:
做这个：
dict['a']['dist'] = 12
回答by chepner
Instead of assigning {'dist':12}to dict['a'], use the updatemethod.
而不是分配{'dist':12}给dict['a']，使用该update方法。
dict['a'].update( {'dist':12} )
This has the advantage of not needing to "break apart" the new dictionary to find which key(s) to insert into the target. Consider:
这具有不需要“分解”新字典来查找要插入到目标中的键的优点。考虑：
a = build_some_dictionary()
for k in a:
dict['a'] = a[k]
vs.
对比
dict['a'].update(a)
回答by Who8MyLunch
Try this:
尝试这个：
dict['a'].update( {'dist': 12} )
dict['a'].update( {'dist': 12} )
