from __future__ import annotations
from typing import NamedTuple
class Result(NamedTuple):
name: str
value: float
def electric_power(voltage: float, current: float, power: float) -> tuple:
"""
This function can calculate any one of the three (voltage, current, power),
fundamental value of electrical system.
examples are below:
>>> electric_power(voltage=0, current=2, power=5)
Result(name='voltage', value=2.5)
>>> electric_power(voltage=2, current=2, power=0)
Result(name='power', value=4.0)
>>> electric_power(voltage=-2, current=3, power=0)
Result(name='power', value=6.0)
>>> electric_power(voltage=2, current=4, power=2)
Traceback (most recent call last):
...
ValueError: Only one argument must be 0
>>> electric_power(voltage=0, current=0, power=2)
Traceback (most recent call last):
...
ValueError: Only one argument must be 0
>>> electric_power(voltage=0, current=2, power=-4)
Traceback (most recent call last):
...
ValueError: Power cannot be negative in any electrical/electronics system
>>> electric_power(voltage=2.2, current=2.2, power=0)
Result(name='power', value=4.84)
"""
if (voltage, current, power).count(0) != 1:
raise ValueError("Only one argument must be 0")
elif power < 0:
raise ValueError(
"Power cannot be negative in any electrical/electronics system"
)
elif voltage == 0:
return Result("voltage", power / current)
elif current == 0:
return Result("current", power / voltage)
elif power == 0:
return Result("power", float(round(abs(voltage * current), 2)))
else:
raise ValueError("Exactly one argument must be 0")
if __name__ == "__main__":
import doctest
doctest.testmod()