Testing a "very close number" in Python with doctest [duplicate]

I'm creating tests for a class using doctest. One of its functions has a random component so its output can vary. I have tried using random.seed() but it changes when I run the file again.

I have tried (too) to use doctest ellipsis but the number can change as the following example:

>>> my_function(params)
9.99
>>> my_function(params)
10.01

Is there a function to test "around" a number, for example using 10 in test and accepting 9.99 and 10.01 as well?