Duplicate dictionary keys in initialization - Python

user_13856191 0
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Is it correct to say that the rightmost/last key-value pair for a given key would always be considered if there are multiple identical keys when initializing a dictionary ?

Example :

Dict = {'A': 5, 'B': 6, 'A': 10}

Will Dict['A'] always be 10 in all python implementations? Where does python enforce this ?

dictionary python
2 Answers

You know that python dict can't contain duplicate keys. So

Dict = {'A': 5, 'B': 6)
Dict.update({'A': 10})
print(Dict['A'])

will result in the last value assigned to the key A:

Output:

10

So the situation is almost like that, python goes through the dictionary during evaluation, and keeps the last value assigned to the keys.

I know dict aren't ordered, but:

  • That doesn't mean python will jump back and forth on the dict when parsing the dict into memory.

  • It will parse through it from left to right to get the collect the data, but it stores the dict without keeping its order.

user_135524700

Python dict can not have duplicate keys. if you try to add the same key again, it will update the existing key with the new value.

Dict = {'A': 5, 'B': 6, 'A': 10}
print(Dict)
{'A': 10, 'B': 6}

the above statement execution is similar to below:

Dict['A'] = 5    
print(Dict)
{'A'=5}

Dict['B'] = 6 
print(Dict)
{'A'=5, 'B'=6}

Dict['A'] = 10
print(Dict)
{'A'=10, 'B'=6}
user_24390040
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