The above example script results in this output to the terminal:
Rounded Results:
Using +=: 6.0663561821
Using a single float(): 6.0663561821
Using a single item(): 6.0663561821
Working Methods:
Adding j, f, c, separately using float(): 6.06635594368
Adding j, f, c, separately using item(): 6.06635594368
The difference Between Adding Methods:
Difference: -2.38418579102e-07

The loss variables j, f, and c are equal to:
j = 2.03060102463
f = 2.00515389442
c = 2.03060102463
When I add them together in python manually, I don’t get the rounded result:
>>> a = 2.03060102463 + 2.00515389442 + 2.03060102463
>>> print(a)
6.06635594368
>>>