Unit Module

The unit module provides the core classes for working with physical quantities.

MetaUnit

class physities.src.unit.unit.MetaUnit

Bases: type

Metaclass enabling operator overloading on Unit classes.

MetaUnit allows Unit types (not instances) to be combined using arithmetic operators to create new composite unit types. This enables syntax like Meter / Second to create a velocity unit type.

scale

The Scale defining this unit type’s dimension and conversion factors.

Examples

>>> # Create composite unit types
>>> Velocity = Meter / Second
>>> Acceleration = Meter / (Second ** 2)
>>> Force = Kilogram * Acceleration

>>> # Scale a unit type
>>> Kilometer = Meter * 1000

scale: Scale

__eq__(other)

Return self==value.

__mul__(other)

__truediv__(other)

__pow__(power, modulo=None)

Unit

class physities.src.unit.unit.Unit(value)

Bases: object

Base class for physical quantity values with units.

Unit represents a physical quantity with both a numeric value and a unit (defined by its Scale). It supports arithmetic operations that properly handle unit conversions and dimensional analysis.

Parameters:

value (float | int)

scale

The Scale defining this unit’s dimension and conversion factors.

value

The numeric value in this unit.

Examples

>>> # Create values with units
>>> distance = Meter(100)
>>> time = Second(10)

>>> # Arithmetic operations
>>> velocity = distance / time  # Creates a m/s value
>>> doubled = velocity * 2
>>> total = Meter(50) + Meter(30)

>>> # Unit conversion
>>> km = Meter(1000).convert(Kilometer)  # 1 km

>>> # Equality across units
>>> Meter(1000) == Kilometer(1)  # True

Pre-defined Units

The following units are available in physities.src.unit:

Base SI Units

Unit	Dimension	Description
Meter	Length	SI base unit of length
Kilogram	Mass	SI base unit of mass
Second	Time	SI base unit of time
Kelvin	Temperature	SI base unit of temperature
Ampere	Electric Current	SI base unit of current
Unity	Amount	Dimensionless unit
Candela	Luminous Intensity	SI base unit of luminosity

Length Units

Gigameter, Megameter, Kilometer, Hectometer, Decameter, Decimeter, Centimeter, Millimeter, Micrometer, Nanometer, Foot, Yard, Inch, Mile, Furlong, Rod

Time Units

Nanosecond, Microsecond, Millisecond, Centisecond, Decisecond, Minute, Hour, Day, Week, Month, Year, Decade, Century, Millennium

Mass Units

Gigagram, Megagram, Tonne, Hectogram, Decagram, Gram, Decigram, Centigram, Milligram, Microgram, Nanogram, Pound, Ounce, Stone, Carat, Grain, Slug

Area Units

Meter2, Kilometer2, Hectare, Centimeter2, Millimeter2, Foot2, Yard2, Inch2, Mile2, Acre

Volume Units

Meter3, Liter, Kiloliter, Milliliter, Centimeter3, Foot3, Gallon, Pint, Barrel

Usage Examples

Creating and Using Units

from physities.src.unit import Meter, Second, Kilogram

# Simple quantities
distance = Meter(100)
time = Second(10)

# Composite units
Velocity = Meter / Second
speed = Velocity(10)

# Operations
total_distance = distance + Meter(50)
doubled = speed * 2

Unit Conversion

from physities.src.unit import Meter, Kilometer

m = Meter(1000)
km = m.convert(Kilometer)
print(km.value)  # 1.0

Creating Custom Units

from physities.src.unit import Meter, Unit
from physities.src.scale import Scale
from physities.src.dimension import Dimension

# Using multiplication
Furlong = Meter * 201.168

# Using Scale directly
class Angstrom(Unit):
    scale = Scale.new(
        dimension=Dimension.new_length(),
        from_base_scale_conversions=(1e-10, 1, 1, 1, 1, 1, 1),
    )
    value = None