Unit-Aware Measurements

3.2.2 · active · verified Sun Apr 12

The `measurement` library (also known as `python-measurement`) provides easy-to-use unit-aware measurement objects in Python. It allows for manipulation and conversion between various SI, US, and Imperial units for quantities like Distance, Weight, Volume, Temperature, Energy, Speed, and Time. The library is currently active, with its latest release (3.2.2) on January 10, 2023, and maintains a stable API.

Warnings

gotcha Measurements are stored internally as floating-point numbers of a (generally) reasonable SI unit. This can lead to slight inaccuracies due to the nature of floating-point representation. Do not use this library for applications requiring extreme precision, such as navigation algorithms for critical systems.
Fix: Be aware of the inherent limitations of floating-point arithmetic. For high-precision scientific or engineering applications, consider libraries designed for arbitrary-precision arithmetic or interval arithmetic if uncertainty propagation is critical.
gotcha When defining custom `MeasureBase` subclasses, ensure `STANDARD_UNIT` and `UNITS` are correctly configured. Incorrect definitions can lead to unexpected unit conversions or a loss of the original unit information if the measurement is stored and retrieved without explicit handling for the custom units.
Fix: Thoroughly test custom `MeasureBase` implementations, especially their interaction with `STANDARD_UNIT` and the `UNITS` dictionary. If preserving the original input unit is crucial, store it alongside the measurement object or use `measurement.utils.guess` to infer the unit upon retrieval where possible.

Install

pip install measurement Install latest version

Imports

Distance

from measurement.measures import Distance

Weight
```
from measurement.measures import Weight
```

Temperature

from measurement.measures import Temperature

MeasureBase
```
from measurement.base import MeasureBase
```
Used for creating custom measurement types.

Quickstart

Demonstrates creating measurement objects, performing basic arithmetic, and converting between different units.

from measurement.measures import Weight, Distance

# Create a Weight object
weight_1 = Weight(lb=125)
weight_2 = Weight(kg=40)

# Perform arithmetic operations
added_together = weight_1 + weight_2
print(f"Weight 1: {weight_1}")
print(f"Weight 2: {weight_2}")
print(f"Sum in pounds: {added_together.lb:.2f} lb")
print(f"Sum in kilograms: {added_together.kg:.2f} kg")

# Create a Distance object and convert units
distance_m = Distance(m=1000)
distance_km = distance_m.km
distance_miles = distance_m.miles

print(f"1000 meters is {distance_km:.2f} km")
print(f"1000 meters is {distance_miles:.2f} miles")

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