[jacobolus]

    Python 3.9.5
    >>> 0.1.hex()
    '0x1.999999999999ap-4'
    >>> 0.2.hex()
    '0x1.999999999999ap-3'
    >>> (0.1 + 0.2).hex()
    '0x1.3333333333334p-2'
    >>> 0.3.hex()
    '0x1.3333333333333p-2'

[colejohnson66]

But they are repeating. So, by definition, they are not exactly representable in a (binary) floating point system. Again, that’s why 0.1 + 0.2 is not 0.3 in binary floating point.

[jacobolus]

These are not "repeating". This is showing the exact binary representation of the nearest double precision value in each case.