To round a number in Python, use the built-in `round()` function.
Here is an example:
```
print(round(3.14159)) # Output: 3
print(round(3.14159, 2)) # Output: 3.14
```
In the first case, `round(3.14159)` rounds to the nearest whole number. In the second case, `round(3.14159, 2)` rounds to two decimal places.
Note that if the number is exactly halfway between two others, it rounds to the nearest even choice. For example `round(2.5)` rounds down to `2`, and `round(3.5)` rounds up to `4`. This is known as round half to even, or “banker’s rounding”.
