Converting the keys of a dictionary from numeric to string

[Peter Otten]

Peter Otten wrote:

> Paul Rubin wrote:
> 
>> Peter Otten <__peter__ at web.de> writes:
>>> assert len(keydict) == len(mydict)
>> 
>> assert set(keydict) == set(mydict)
> 
> The weaker check is O(1), and, combined with the succeeding for loop,
> implies the above.

Sorry, I have to take that back:

Python 3.6.0b1+ (3.6:5c92f9e0a8b1, Sep 13 2016, 14:44:51) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> keydict = { 1: "Joseph", "Joseph": "Michael", 3: "John" }
>>> mydict = { 1: 1000, 2: 2000, 3: 3000 }
>>> assert len(keydict) == len(mydict)
>>> assert set(keydict) == set(mydict)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AssertionError
>>> for k, v in keydict.items():
...     mydict[v] = mydict.pop(k)
... 
>>> print(mydict)
{2: 2000, 'Michael': 1000, 'John': 3000}