Add OOP-based calculator implementation

Calculator/calculator_oop.py

@@ -0,0 +1,99 @@
+# calculator_oop.py
+class Calculator:
+    def _init_(self, value: float = 0.0):
+        self.value = float(value)
+
+    def add(self, x: float):
+        self.value = self.value + float(x)
+        return self.value
+
+    def subtract(self, x: float):
+        self.value = self.value - float(x)
+        return self.value
+
+    def multiply(self, x: float):
+        self.value = self.value * float(x)
+        return self.value
+
+    def divide(self, x: float):
+        x = float(x)
+        if x == 0:
+            raise ZeroDivisionError("Cannot divide by zero")
+        self.value = self.value / x
+        return self.value
+
+    def exponent(self, x: float):
+        self.value = self.value ** float(x)
+        return self.value
+
+    def nth_root(self, n: float):
+        n = float(n)
+        if n == 0:
+            raise ValueError("0-th root is undefined")
+        # nth root = value ** (1/n)
+        self.value = self.value ** (1.0 / n)
+        return self.value
+
+    def set_value(self, x: float):
+        self.value = float(x)
+        return self.value
+
+    def get_value(self):
+        return self.value
+
+# CLI wrapper (keeps behaviour similar to original main)
+def cli():
+    ops = {
+        "+": "add",
+        "-": "subtract",
+        "*": "multiply",
+        "/": "divide",
+        "^": "exponent",
+        "v": "nth_root"
+    }
+
+    calc = Calculator()
+    try:
+        initial = float(input("What's the first number? "))
+    except ValueError:
+        print("Please enter a number.")
+        return
+
+    calc.set_value(initial)
+
+    should_continue = True
+    while should_continue:
+        print("Available operations:", " ".join(ops.keys()))
+        op = input("Pick an operation: ").strip()
+        if op not in ops:
+            print("Unknown operation. Try again.")
+            continue
+
+        try:
+            nxt = float(input("What's the next number? "))
+        except ValueError:
+            print("Please enter a number.")
+            continue
+
+        try:
+            if op == "v":
+                result = calc.nth_root(nxt)
+                print(f"{nxt} {op} {calc.get_value()} = {result}")
+            else:
+                method = getattr(calc, ops[op])
+                result = method(nxt)
+                print(f"{calc.get_value()} {op} {nxt} = {result}")
+        except Exception as e:
+            print("Error:", e)
+            # do not crash — let user try again
+            continue
+
+        cont = input("Type 'y' to continue calculating with result, or 'n' to start new: ").strip().lower()
+        if cont == "y":
+            # keep calc.value as-is and continue
+            pass
+        else:
+            should_continue = False
+
+if _name_ == "_main_":
+    cli()