Python · Math, random & Decimal

You set decimal.getcontext().prec = 3 then compute Decimal("1.23456789") * Decimal("2.3456789"). What does prec control, and what surprises people?

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More in Math, random & Decimal

What does this print? ``` print(round(0.5), round(2.5)) print(round(1.5), round(3.5)) ```

You need to round prices half-up (2.5 -> 3, never 2). Why won't built-in round() do it, and what does?

What is the difference in result and return type between math.floor(-2.5), math.trunc(-2.5), and math.ceil(-2.5)?

You compare two values near zero with math.isclose(a, 0.0). Why might it return False even when a is tiny, and how do you fix it?

What does this print? ``` import math nan = math.nan print(nan == nan) print(math.isnan(nan)) ```

What does this print? ``` from decimal import Decimal print(Decimal("0.1") + Decimal("0.2")) ```

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