Python 3.5 adds the `math.isclose`

and `cmath.isclose`

functions as described in PEP 485.

If you’re using an earlier version of Python, the equivalent function is given in the documentation.

```
def isclose(a, b, rel_tol=1e-09, abs_tol=0.0):
return abs(a-b) <= max(rel_tol * max(abs(a), abs(b)), abs_tol)
```

`rel_tol`

is a relative tolerance, it is multiplied by the greater of the magnitudes of the two arguments; as the values get larger, so does the allowed difference between them while still considering them equal.

`abs_tol`

is an absolute tolerance that is applied as-is in all cases. If the difference is less than either of those tolerances, the values are considered equal.