Add feature to print result parts to console

[paul019]

Resolve #28

[Splines]

Would it be beneficial to also have access to the value and the uncertainties as numeric values, not only as strings? For example,

res = wiz.res(3.14, ...)
# Some further calculation
print(res.value + 1.0)

In this case, we should make very clear in the docs that the object returned by wiz.res() is non-modifiable, e.g. you cannot set res.value = 42 afterwards and expect the underlying value to change. It is read-only.

But maybe that is overkill and we should leave it at strings. One could also argue that the user already knows the numerical value upfront, so they could instead just assign it the a local variable before passing it to wiz.res() and would be good to go... This would also avoid confusion about the modifiability ob the object returned by wiz.res() since when you only get back strings, you probably don't expect that this would modify the underlying valueres.value = "42.0". In that case, maybe we can even drop the "str" part of the method names? Since the datatype is clear by the method signature -> str.

[paul019]

But maybe that is overkill and we should leave it at strings.

I agree :-)