bytes() doesn't accept a dict as parameter. If you attempt to pass one, you receive a TypeError with the baffling message "'str' object cannot be interpreted as an integer".

 >> bytes({'a':1})
 Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
 TypeError: 'str' object cannot be interpreted as an integer

bytes() accepts:

1. An integer.
2. An object supporting the buffer protocol.
3. An iterable of integers in the range 0 to 255.

Dict is an iterable. But iterating it produces string object which cannot be interpreted as an integer.

You can in fact pass a dict to bytes(), as long as the keys are ints in the correct range:

>>> bytes({0:10, 1:20})
b'\x00\x01'

I'm not claiming it's very useful, but it does conform to the docs. I'm not sure the error message can be improved, so I suggest closing this issue.

>  I'm not sure the error message can be improved, so I suggest closing this issue.

I concur.