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math.trunc

rounding

Cuts off the fractional part — rounding towards zero. math.trunc(2.9) → 2, math.trunc(-2.9) → -2.

Syntax

math.trunc(x)

For positive numbers trunc and floor are indistinguishable; the difference shows up only on negatives: trunc(-3.5) is -3 while floor(-3.5) is -4. On a float trunc does exactly what int(x) does, which is why it rarely appears in beginner code — it is used to state the intent explicitly or to hook into a custom class's __trunc__.

Examples

import math
print(math.trunc(3.9))   # → 3
print(math.trunc(-3.9))  # → -3
print(math.trunc(3.1))   # → 3
print(math.trunc(-3.1))  # → -3
print(math.trunc(0.9))   # → 0
print(math.trunc(-0.5))  # → 0

See also

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