unittest: Proposal to add failUnlessNear

[Roy Smith]

"John Roth" <newsgroups at jhrothjr.com> wrote:

> Because the "distance" between two floats is
> 
> abs(a - b)
> 
> while the "distance" between two complex numbers
> 
> is something like
> 
>         math.sqrt(diff.real ** 2 + diff.imag ** 2)

The distance between two complex numbers is indeed computed using the 
pythagorean formula, but all that is hidden from view when you just say 
"abs (a - b)".

>>> import math
>>> a = 1 + 3j
>>> b = -3 + 1j
>>> math.sqrt ((a.real - b.real) ** 2 + (a.imag - b.imag) ** 2)
4.4721359549995796
>>> abs (a-b)
4.4721359549995796