| """Unit conversion tool using pint. |
| |
| Pint's UnitRegistry loads ~1000 unit definitions on construction (~50ms), |
| so we use the same lazy + cached pattern as tavily_search and wikipedia: |
| module-level _ureg, _get_ureg() initializes on first call. |
| Errors returned as Observation strings. |
| """ |
| from . import tool |
|
|
| _ureg = None |
|
|
|
|
| def _get_ureg(): |
| """Lazy-initialize the pint UnitRegistry. The `import pint` is deferred |
| to first call so pytest collection works without pint installed.""" |
| global _ureg |
| if _ureg is None: |
| import pint |
| _ureg = pint.UnitRegistry() |
| return _ureg |
|
|
|
|
| @tool |
| def unit_convert(value: float, from_unit: str, to_unit: str) -> str: |
| """Convert a value from one unit to another. |
| |
| Accepts most physical units pint knows: meter, mile, kilometer, second, |
| minute, hour, kilogram, pound, celsius, fahrenheit, and combinations |
| like meter/second, kilogram*meter/second**2. |
| |
| Examples: |
| unit_convert(60, "mile/hour", "meter/second") -> "26.82..." |
| unit_convert(100, "kilometer", "mile") -> "62.14..." |
| unit_convert(212, "fahrenheit", "celsius") -> "100.0..." |
| """ |
| try: |
| ureg = _get_ureg() |
| quantity = value * ureg(from_unit) |
| converted = quantity.to(to_unit) |
| return str(converted.magnitude) |
| except Exception as e: |
| return f"Unit convert error: {type(e).__name__}: {e}" |
|
|
