Create app.py

app.py

@@ -0,0 +1,104 @@
+import gradio as gr
+
+# -----------------------
+# Data
+# -----------------------
+INVENTORY = [
+    (101, "Hammer", 120),
+    (102, "Screwdriver Set", 350),
+    (103, "Drill Machine", 2500),
+    (104, "Pliers", 180),
+    (105, "Wrench", 220),
+]
+
+# Index by ID for quick lookup
+INV_BY_ID = {item_id: (name, price) for item_id, name, price in INVENTORY}
+
+# -----------------------
+# Cart state helpers
+# -----------------------
+def fmt_cart(cart):
+    if not cart:
+        return "— (empty) —"
+    lines = [f"{i}. [{item_id}] {name} — ${price}" for i, (item_id, name, price) in enumerate(cart)]
+    return "\n".join(lines)
+
+def total_cost(cart):
+    return sum(price for _, _, price in cart)
+
+# -----------------------
+# Actions
+# -----------------------
+def add_to_cart(item_id, cart):
+    cart = cart or []
+    msg = ""
+    try:
+        item_id = int(item_id)
+    except (TypeError, ValueError):
+        return fmt_cart(cart), "Invalid ID: enter a number.", "", total_cost(cart), cart
+
+    if item_id not in INV_BY_ID:
+        return fmt_cart(cart), f"ID {item_id} not found in inventory.", "", total_cost(cart), cart
+
+    name, price = INV_BY_ID[item_id]
+    cart.append((item_id, name, price))
+    return fmt_cart(cart), f"Added: [{item_id}] {name} (${price})", "", total_cost(cart), cart
+
+def remove_from_cart(index, cart):
+    cart = cart or []
+    msg_ok, msg_err = "", ""
+    try:
+        index = int(index)
+    except (TypeError, ValueError):
+        return fmt_cart(cart), "", "Invalid index: enter a number.", total_cost(cart), cart
+
+    if 0 <= index < len(cart):
+        item_id, name, price = cart.pop(index)
+        msg_ok = f"Removed: [{item_id}] {name} (${price})"
+    else:
+        msg_err = f"Index {index} not in cart range (0–{max(len(cart)-1,0)})."
+    return fmt_cart(cart), msg_ok, msg_err, total_cost(cart), cart
+
+# -----------------------
+# UI
+# -----------------------
+with gr.Blocks(title="Hardware Store Billing") as demo:
+    gr.Markdown("## Hardware Store Billing\nAdd items by **Inventory ID**; remove by **cart index** (0-based).")
+
+    with gr.Row():
+        add_id = gr.Number(label="Enter Inventory ID to Add to Cart", value=0, precision=0)
+        rem_idx = gr.Number(label="Enter Index ID to Remove from Cart", value=0, precision=0)
+
+    with gr.Row():
+        btn_add = gr.Button("Add to Cart", variant="primary")
+        btn_rem = gr.Button("Remove from Cart")
+
+    cart_box = gr.Textbox(label="Your Cart", value="— (empty) —", lines=10)
+    add_msg = gr.Textbox(label="Add Item Message", interactive=False)
+    rem_msg = gr.Textbox(label="Remove Item Message", interactive=False)
+    total = gr.Number(label="Total Cost", value=0, interactive=False, precision=0)
+
+    # Keep cart in state
+    cart_state = gr.State([])
+
+    btn_add.click(
+        fn=add_to_cart,
+        inputs=[add_id, cart_state],
+        outputs=[cart_box, add_msg, rem_msg, total, cart_state]
+    )
+
+    btn_rem.click(
+        fn=remove_from_cart,
+        inputs=[rem_idx, cart_state],
+        outputs=[cart_box, add_msg, rem_msg, total, cart_state]
+    )
+
+    with gr.Accordion("Inventory", open=False):
+        gr.Dataframe(
+            headers=["ID", "Name", "Price"],
+            value=INVENTORY,
+            wrap=True
+        )
+
+if __name__ == "__main__":
+    demo.launch()