Update app.py

app.py

@@ -1,18 +1,27 @@
 import gradio as gr
-from transformers import AutoTokenizer, AutoModelForSequenceClassification
+from transformers import AutoTokenizer, AutoModelForSequenceClassification, GPT2LMHeadModel
 import torch
 import math
 
-# Load the ChatGPT detector model
+# -------------------------------
+# Load Models
+# -------------------------------
+
+# ChatGPT detector model (RoBERTa)
 detector_name = "Hello-SimpleAI/chatgpt-detector-roberta"
 detector_tokenizer = AutoTokenizer.from_pretrained(detector_name)
 detector_model = AutoModelForSequenceClassification.from_pretrained(detector_name)
 
-# Load GPT-2 for perplexity calculation
+# GPT-2 for perplexity calculation
 gpt2_name = "gpt2"
 gpt2_tokenizer = AutoTokenizer.from_pretrained(gpt2_name)
 gpt2_model = GPT2LMHeadModel.from_pretrained(gpt2_name)
 
+
+# -------------------------------
+# Helper Functions
+# -------------------------------
+
 def compute_perplexity(text: str) -> float:
     """Calculate perplexity using GPT-2 language model."""
     enc = gpt2_tokenizer(text, return_tensors="pt", truncation=True, max_length=512)
@@ -48,6 +57,11 @@ def analyze_text(user_text: str):
         "Final Human Probability (avg)": round(final_human * 100, 2),
     }
 
+
+# -------------------------------
+# Gradio UI
+# -------------------------------
+
 with gr.Blocks() as demo:
     gr.Markdown("# 🔍 Free AI vs Human Text Detector (Demo)")