ch06

ch06/oop/dataclass.py

@@ -0,0 +1,25 @@
+# oop/dataclass.py
+from dataclasses import dataclass
+
+
+@dataclass
+class Body:
+    '''Class to represent a physical body.'''
+    name: str
+    mass: float = 0.  # Kg
+    speed: float = 1.  # m/s
+
+    def kinetic_energy(self) -> float:
+        return (self.mass * self.speed ** 2) / 2
+
+
+body = Body('Ball', 19, 3.1415)
+print(body.kinetic_energy())  # 93.755711375 Joule
+print(body)  # Body(name='Ball', mass=19, speed=3.1415)
+
+
+"""
+$ python dataclass.py
+93.755711375
+Body(name='Ball', mass=19, speed=3.1415)
+"""