Python 3.3+timefunction

time.perf_counter()

clocks and timing

A high-resolution counter in seconds for measuring short intervals: how long a piece of code took.

Syntax

time.perf_counter() -> float

The standard way to time code: t0 = perf_counter() before, the difference after. It counts real (wall) time, including sleep and waiting for input; pure CPU time comes from process_time(). A single measurement is noisy — repeat micro-benchmarks many times or use timeit. In CPython 3.13+ it is the same clock as monotonic(), but portable code should not rely on that.

Examples

import time
t0 = time.perf_counter()
total = sum(range(100_000))
elapsed = time.perf_counter() - t0
print(elapsed >= 0)  # → True
print(f'{elapsed:.4f} с')  # → ? 0.0012 с — зависит от машины

See also

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