round ( Numeric_expression )
round ( Numeric_expression, Integer_expression )

return Numeric_expression

This function rounds a floating point number. The optional second argument (an integer) defines how many decimal places to round to.

a = 3.1415926535
print round(a)
print round(a,1)
print round(a,2)
print round(a,3)
print round(a,4)

3.0
3.1
3.14
3.142
3.1416