benchbro 0.1.0

Benchmark library and CLI

benchbro

benchbro is a Python benchmarking library and CLI with pytest-style discovery and rich terminal output.

Quick start

Install dependencies:

uv sync --group dev

Create benchmark cases in any importable module:

from benchbro import Case

case = Case(name="hashing", case_type="cpu", metric_type="time", tags=["fast", "core"])


@case.input()
def payload() -> bytes:
    return b"benchbro"


@case.benchmark()
def sha1(payload: bytes) -> str:
    import hashlib

    return hashlib.sha1(payload).hexdigest()


@case.benchmark()
def sha256(payload: bytes) -> str:
    import hashlib

    return hashlib.sha256(payload).hexdigest()

Regression thresholds default to 50.0 percent warning and 100.0 percent error at the case level, and can be overridden per benchmark:

case = Case(name="hashing", warning_threshold_pct=5.0, regression_threshold_pct=10.0)

@case.benchmark(warning_threshold_pct=2.0, regression_threshold_pct=3.0)
def critical_path(payload: bytes) -> str:
    ...

GC is disabled during measured iterations by default. To keep the interpreter GC behavior unchanged, set:

Case(name="hashing", gc_control="inherit")

Run benchmarks:

uv run benchbro --repeats 10 --warmup 2

When no target is provided, benchbro discovers benchmarks from:

• benchmarks/**/*.py (relative to repo root)

benchbro compares against the baseline by default (.benchbro/baseline.json). If the baseline is missing, benchbro creates it automatically. If new cases/benchmarks are introduced later, missing entries are merged into baseline. Pass --new-baseline to replace the entire baseline with the current run.

By default, regular runs do not write artifacts. Use explicit output flags (--output-json, --output-csv, --output-md) when needed.

The baseline is always written to:

• .benchbro/baseline.json

If requested, markdown output can also be written with --output-md.

JSON artifacts include environment metadata for reproducibility (Python/runtime/platform/CPU fields) both at run level and on each benchmark entry.

CLI basics

Run selected cases/tags and write outputs:

uv run benchbro my_benchmarks.py \
  --case hashing \
  --tag fast \
  --output-json artifacts/current.json \
  --output-csv artifacts/current.csv \
  --output-md artifacts/current.md

Compare against baseline:

uv run benchbro my_benchmarks.py

Regression status uses each benchmark's effective thresholds (benchmark override -> case threshold -> defaults):

• warning default: 50%
• error threshold default: 100%

The comparison table shows warning and threshold values for each row.

End-to-end example

For a complete runnable workflow (baseline + candidate comparison), use:

• examples/README.md
• make examples