Comparing two floats in python

I am learning how to use Python 3 for scientific
computing. In an exercise, I am asked to implement a function that returns the real or
complex roots of a quadratic equation, as well as implementing a test function to verify
the accuracy of my function. I am having troubles comparing two floats
values.

Here is my
function:

def roots(a, b, c):
 from
            numpy.lib.scimath import sqrt #Handles real and complex numbers
 r = sqrt(b**2
            - 4*a*c)
 sol_1 = (-b + r)/(2*a)
 sol_2 = (-b - r)/(2*a)

            return sol_1, sol_2

Here is my
test_function:

def
            test_roots_real():
 a = 5; b = 6; c = 1 #test parameters (roots should be
            -0.2(+) and -1(-)
 exact_sol_1 = -0.2
 exact_sol_2 = -1

            sol_1, sol_2 = roots(a,b,c)
 success = (abs(exact_sol_1 - sol_1) < 1E-14)
            and (abs(exact_sol_2 - sol_2) < 1E-14) #Never use == with floats!
 msg =
            'Cannot find accurate solutions'
 assert success,
            msg
test_roots_real()

The
problem is when I compare the computed solutions with their respective exact solutions.

If I run roots(5,6,1), I get
(-0.20000000000000001, -1.0)

With
a threshold of 1E-14, there is no problem (as expected).
However, if I change it to something much smaller (e.g. 1E-25),
I don't get an error when I should, no? I was wondering what is happening, and I would
greatly appreciate the community's feedback.

Thank
you!

EDIT:

Also, how could I
use the same logic but compare two complex numbers? I never work with them.