Add class for representing Voltage quantities

Signed-off-by: Sahas Subramanian <[email protected]>

Author: shsms

src/frequenz/sdk/timeseries/_quantities.py

@@ -402,3 +402,67 @@ def as_milliamperes(self) -> float:
             The current in milliamperes.
         """
         return self._base_value * 1e3
+
+
+class Voltage(Quantity, exponent_unit_map={0: "V", -3: "mV", 3: "kV"}):
+    """A voltage quantity."""
+
+    @classmethod
+    def from_volts(cls, volts: float) -> Self:
+        """Initialize a new voltage quantity.
+
+        Args:
+            volts: The voltage in volts.
+
+        Returns:
+            A new voltage quantity.
+        """
+        return cls(value=volts, exponent=0)
+
+    @classmethod
+    def from_millivolts(cls, millivolts: float) -> Self:
+        """Initialize a new voltage quantity.
+
+        Args:
+            millivolts: The voltage in millivolts.
+
+        Returns:
+            A new voltage quantity.
+        """
+        return cls(value=millivolts, exponent=-3)
+
+    @classmethod
+    def from_kilovolts(cls, kilovolts: float) -> Self:
+        """Initialize a new voltage quantity.
+
+        Args:
+            kilovolts: The voltage in kilovolts.
+
+        Returns:
+            A new voltage quantity.
+        """
+        return cls(value=kilovolts, exponent=3)
+
+    def as_volts(self) -> float:
+        """Return the voltage in volts.
+
+        Returns:
+            The voltage in volts.
+        """
+        return self._base_value
+
+    def as_millivolts(self) -> float:
+        """Return the voltage in millivolts.
+
+        Returns:
+            The voltage in millivolts.
+        """
+        return self._base_value * 1e3
+
+    def as_kilovolts(self) -> float:
+        """Return the voltage in kilovolts.
+
+        Returns:
+            The voltage in kilovolts.
+        """
+        return self._base_value / 1e3

tests/timeseries/test_quantities.py

@@ -5,7 +5,7 @@
 
 import pytest
 
-from frequenz.sdk.timeseries._quantities import Current, Power, Quantity
+from frequenz.sdk.timeseries._quantities import Current, Power, Quantity, Voltage
 
 
 class Fz1(
@@ -176,3 +176,20 @@ def test_current() -> None:
     assert current == Current.from_milliamperes(6000.0)
     assert current == Current.from_amperes(6.0)
     assert current != Current.from_amperes(5.0)
+
+
+def test_voltage() -> None:
+    """Test the voltage class."""
+    voltage = Voltage.from_millivolts(0.0000002)
+    assert f"{voltage:.9}" == "0.0000002 mV"
+    voltage = Voltage.from_kilovolts(600000.0)
+    assert f"{voltage}" == "600000 kV"
+
+    voltage = Voltage.from_volts(6.0)
+    assert voltage.as_volts() == 6.0
+    assert voltage.as_millivolts() == 6000.0
+    assert voltage.as_kilovolts() == 0.006
+    assert voltage == Voltage.from_millivolts(6000.0)
+    assert voltage == Voltage.from_kilovolts(0.006)
+    assert voltage == Voltage.from_volts(6.0)
+    assert voltage != Voltage.from_volts(5.0)