data class

src/advance/data_class_generation.py

@@ -0,0 +1,50 @@
+
+from dataclasses import dataclass, make_dataclass
+from typing import ClassVar, Optional
+
+
+@dataclass
+class Car:
+    # Instance variables (required first)
+    name: str
+    color: str
+
+    year: int = 2025                  # default value
+    price: Optional[float] = None     # nullable (Optional)
+
+    # Class variable (static) - shared by all cars
+    extra_wheels: int = 1
+    # Car(name='BMW', color='black', year=2025, price=None, extra_wheels=1)
+
+    wheels: ClassVar[int] = 4   # won’t appear in __init__, shared by all
+    # Car(name='BMW', color='black', year=2025, price=None, extra_wheels=1)
+    # Custom string output
+
+
+car = Car(name="BMW", color="black")
+print(car)
+
+
+# -----------------------------------------------------
+
+
+# fields dynamic
+
+field_definitions = [
+    ("name", str, "Unknown"),
+    ("color", str, "Black"),
+    ("year", int, 2025),
+    ("price", Optional[float], None),
+]
+
+# Add more fields dynamically (simulate 30+ attributes)
+for i in range(5, 35):
+    field_definitions.append((f"attr{i}", Optional[str], None))
+
+# Step 2: Create dataclass dynamically
+Bus = make_dataclass("Bus", field_definitions)
+
+bus = Bus()
+
+bus.attr32 = "46"
+print(bus)