String to Float, without introducing errors

[dn]

On 18/12/2022 01.39, Peter J. Holzer wrote:
> On 2022-12-17 12:51:17 +0100, Paul St George wrote:
>> I have a large/long array of numbers in an external file. The numbers
>> look like this:
>>
>> -64550.727
>> -64511.489
>> -64393.637
> [...]
>>
>> When I bring the numbers into my code, they are Strings. To use the
>> numbers in my code, I want to change the Strings to Float type because
>> the code will not work with Strings but I do not want to change the
>> numbers in any other way.
> 
>>>> s = "-64550.727"
>>>> f = float(s)
>>>> f
> -64550.727
>>>> type(f)
> <class 'float'>
> 
> (Contrary to the other people posting in this thread I don't think float
> is the wrong type for the job. It might be, but you haven't given enough
> details to tell whether the inevitable rounding error matters or not. In
> my experience in almost all cases where people think it matters it
> really doesn't.)

Agreed: (ultimately) insufficient information-provided.
(but that probably doesn't matter either - as the OP seems to have come 
to a decision)


Agreed: probably doesn't matter.


'The world' agrees with both, having decided that Numerical Analysis is 
no-longer a necessary ComSc study.

In the ?good, old, days Numerical Analysis included contemplation of the 
difficulties and differences between "precision" and "accuracy". Thus, 
the highly accurate calculation of less-than precise numbers - or was it 
precise values subject to less than accurate computation?
(rhetorical!)

Sort of like giving highly-accurate answers to a less-than precise 
(complete) question, by presuming can ignore the latter.

-- 
Regards,
=dn