It appears that rather than a native SymPy round() function, SymPy overloads the native Python round() function so that it accepts and returns Sympy number types. In the 1.9 documentation I find th ...

Example Round Function A more helpful function for rounding in python. Can also be transferred to other languages.

This quick tutorial shows users how to round in Python using one of three methods. You'll also discover how to do more with the math module.