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CodeDrome/sibaseunit.py

Created August 16, 2022 11:21
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sibaseunit.py
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sibaseunit.py
from types import MappingProxyType
class SIBaseUnit(object):
"""
The SIBaseUnit class provides properties for
representing values of the 7 SI base units,
multiplier prefixes such as kilo and nano,
methods for string representation,
and arithmetic and comparison operators
"""
quantities = MappingProxyType({
"time":
{"name": "time", "baseunit": "second", "symbol": "s"},
"length":
{"name": "length", "baseunit": "metre", "symbol": "m"},
"mass":
{"name": "mass", "baseunit": "gram", "symbol": "g"},
"electric current":
{"name": "electric current", "baseunit": "ampere", "symbol": "A"},
"thermodynamic temperature":
{"name": "thermodynamic temperature", "baseunit": "kelvin", "symbol": "K"},
"amount of substance":
{"name": "amount of substance", "baseunit": "mole", "symbol": "mol"},
"luminous intensity":
{"name": "luminous intensity", "baseunit": "candela", "symbol": "cd"}
})
prefixes = MappingProxyType({
"yotta": {"name": "yotta", "power": 24, "symbol": "Y"},
"zetta": {"name": "zetta", "power": 21, "symbol": "Z"},
"exa": {"name": "exa", "power": 18, "symbol": "E"},
"peta": {"name": "peta", "power": 15, "symbol": "P"},
"tera": {"name": "tera", "power": 12, "symbol": "T"},
"giga": {"name": "giga", "power": 9, "symbol": "G"},
"mega": {"name": "mega", "power": 6, "symbol": "M"},
"kilo": {"name": "kilo", "power": 3, "symbol": "k"},
"hecto": {"name": "hecto", "power": 2, "symbol": "h"},
"deca": {"name": "deca", "power": 1, "symbol": "da"},
"none": {"name": "none", "power": 0, "symbol": ""},
"deci": {"name": "deci", "power": -1, "symbol": "d"},
"centi": {"name": "centi", "power": -2, "symbol": "c"},
"milli": {"name": "milli", "power": -3, "symbol": "m"},
"micro": {"name": "micro", "power": -6, "symbol": "undefined"},
"nano": {"name": "nano", "power": -9, "symbol": "n"},
"pico": {"name": "pico", "power": -12, "symbol": "p"},
"femto": {"name": "femto", "power": -15, "symbol": "f"},
"atto": {"name": "atto", "power": -18, "symbol": "a"},
"zepto": {"name": "zepto", "power": -21, "symbol": "z"},
"yocto": {"name": "yocto", "power": -24, "symbol": "y"}
})
def __init__(self, quantity, prefix, value = 0):
"""
quantity is one of the quantities values,
eg SIBaseUnit.quantities["length"]
prefix is one of the prefixes values,
eg SIBaseUnit.prefixes["centi"]
"""
self._quantity = quantity
self._prefix = prefix
self._value_base = self.prefixed_value_to_base(value, prefix)
@property
def value(self):
return self.base_value_to_prefixed(self._value_base, self._prefix)
@value.setter
def value(self, value):
self._value_base = self.prefixed_value_to_base(value, self._prefix)
@property
def prefix(self):
return self._prefix
def __repr__(self):
return f'SIBaseUnit("{self._quantity}","{self._prefix}",{self.base_value_to_prefixed()})'
def __str__(self):
return self.string_short()
def string_long(self):
if self._prefix['name'] != "none":
prefix = self._prefix['name']
else:
prefix = ""
return f"{self.base_value_to_prefixed(self._value_base, self._prefix):g} {prefix}{self._quantity['baseunit']}"
def string_short(self):
if self._prefix['name'] != "none":
symbol = self._prefix['symbol']
else:
symbol = ""
return f"{self.base_value_to_prefixed(self._value_base, self._prefix ):g}{symbol}{self._quantity['symbol']}"
# selection of arithmetic and comparison dunder methods
def __add__(self, other):
self.__check_quantities(other)
base_1 = self.prefixed_value_to_base(self.value, self.prefix)
base_2 = self.prefixed_value_to_base(other.value, other.prefix)
base_total = base_1 + base_2
prefixed_total = self.base_value_to_prefixed(base_total, self.prefix)
return SIBaseUnit(self._quantity, self._prefix, prefixed_total)
def __sub__(self, other):
self.__check_quantities(other)
base_1 = self.prefixed_value_to_base(self.value, self.prefix)
base_2 = self.prefixed_value_to_base(other.value, other.prefix)
base_difference = base_1 - base_2
prefixed_difference = self.base_value_to_prefixed(base_difference, self.prefix)
return SIBaseUnit(self._quantity, self._prefix, prefixed_difference)
def __mul__(self, value):
base_1 = self.prefixed_value_to_base(self.value, self.prefix)
base_product = base_1 * value
prefixed_product = self.base_value_to_prefixed(base_product, self.prefix)
return SIBaseUnit(self._quantity, self._prefix, prefixed_product)
def __rmul__(self, value):
base_1 = self.prefixed_value_to_base(self.value, self.prefix)
base_product = base_1 * value
prefixed_product = self.base_value_to_prefixed(base_product, self.prefix)
return SIBaseUnit(self._quantity, self._prefix, prefixed_product)
def __truediv__(self, value):
base_1 = self.prefixed_value_to_base(self.value, self.prefix)
base_quotient = base_1 / value
prefixed_quotient = self.base_value_to_prefixed(base_quotient, self.prefix)
return SIBaseUnit(self._quantity, self._prefix, prefixed_quotient)
def __lt__(self, other):
self.__check_quantities(other)
base_1 = self.prefixed_value_to_base(self.value, self.prefix)
base_2 = self.prefixed_value_to_base(other.value, other.prefix)
return base_1 < base_2
def __le__(self, other):
self.__check_quantities(other)
base_1 = self.prefixed_value_to_base(self.value, self.prefix)
base_2 = self.prefixed_value_to_base(other.value, other.prefix)
return base_1 <= base_2
def __eq__(self, other):
self.__check_quantities(other)
base_1 = self.prefixed_value_to_base(self.value, self.prefix)
base_2 = self.prefixed_value_to_base(other.value, other.prefix)
return base_1 == base_2
def __gt__(self, other):
self.__check_quantities(other)
base_1 = self.prefixed_value_to_base(self.value, self.prefix)
base_2 = self.prefixed_value_to_base(other.value, other.prefix)
return base_1 > base_2
def __ge__(self, other):
self.__check_quantities(other)
base_1 = self.prefixed_value_to_base(self.value, self.prefix)
base_2 = self.prefixed_value_to_base(other.value, other.prefix)
return base_1 >= base_2
def __ne__(self, other):
self.__check_quantities(other)
base_1 = self.prefixed_value_to_base(self.value, self.prefix)
base_2 = self.prefixed_value_to_base(other.value, other.prefix)
return base_1 != base_2
def __check_quantities(self, other):
if self._quantity != other._quantity:
raise TypeError('Both units must be of same quantity')
def output(self):
print(f"quantity: {self._quantity['name']}")
print(f"base unit: {self._quantity['baseunit']}")
print(f"prefix name: {self._prefix['name']}")
print(f"prefix power: {self._prefix['power']}")
print(f"value_base: {self._value_base:f}")
print(f"value prefixed: {self.base_value_to_prefixed(self._value_base, self._prefix):f}")
@staticmethod
def prefixed_value_to_base(value_prefixed, prefix):
return value_prefixed * 10 ** prefix['power']
@staticmethod
def base_value_to_prefixed(value_base, prefix):
return value_base / (10 ** prefix['power'])
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