How to add new values to key in a dict?

Question

If I had a sample dict:

mydict = {1:{2:'A'}}

how can I add new data to key 1 so that it can be like:

mydict = {1:{2:'A'},{3:'B'}} 

When I do mydict.update({3:'B'})

I get: {1: {2: 'A'}, 3: 'B'} not {1: {2: 'A'}, {3: 'B'}}

If I try .update using the same key it just replaces the data:

mydict.update({1:{3:'B'}}) becomes {1: {3: 'B'}}

Answer 1

There already have a good library for you:

from collections import defaultdict

d = defaultdict(dict)
d['person']['name']='frank'
d['person']['age']='age'

and then you can easily get the data from your 2 key! like:

print d['person']['name']

Answer 2

When you do mydict.update({3:'B'}) you are updating the wrong dictionary.

It looks like you want to update the dictionary in mydict[1]

This is assuming you actually want a result of {1: {2: 'A', 3: 'B'}} as your example {1: {2: 'A'}, {3: 'B'}} is not valid python.

So try mydict[1].update({3:'B'})

Answer 3

只需添加

 mydict[1].update({3:'B'})

Answer 4

  mydict ={2:'a',3:'b'} d={1:mydict} print (d) {1: {2: 'a', 3: 'b'}} to update more key:values you can add to mydict