Can one output something other than 'nan' for not a number values?

[Grant Edwards]

On 2024-02-17, Cameron Simpson via Python-list <python-list at python.org> wrote:
> On 16Feb2024 22:12, Chris Green <cl at isbd.net> wrote:
>>I'm looking for a simple way to make NaN values output as something
>>like '-' or even just a space instead of the string 'nan'. [...]
>>
>>    Battery Voltages and Currents
>>    Leisure Battery - 12.42 volts  -0.52 Amps
>>    Starter Battery -   nan volts    nan Amps
>>
>>What I would like is for those 'nan' strings to be just a '-' or
>>something similar.
>
> The simplest thing is probably just a function writing it how you want 
> it:
>
>      def float_s(f):
>          if isnan(f):
>              return "-"
>          return str(f)

He's obviouisly using a formatting feature to control columns and
decimal places, so I doubt that 'str(f)' is going to meet the need.

I tried monkey-patching the __format__ method of the 'float' type, but
it's immutable -- so that didn't work.

Is float.__format__() what's used by f-strings, the % operator, etc.?

--
Grant