README.md

@@ -1,14 +1,14 @@
 # 🧠 AI Lab – Transformers CLI Playground
 
 > A **pedagogical and technical project** designed for AI practitioners and students to experiment with Hugging Face Transformers through an **interactive Command‑Line Interface (CLI)**.  
-> This playground provides ready‑to‑use NLP pipelines (Sentiment Analysis, Named Entity Recognition, Text Generation, Fill‑Mask, Moderation, etc.) in a modular, extensible, and educational codebase.
+> This playground provides ready‑to‑use NLP pipelines (Sentiment Analysis, Named Entity Recognition, Text Generation, Fill‑Mask, Question Answering, Moderation, etc.) in a modular, extensible, and educational codebase.
 
 ---
 
 ## 📚 Overview
 
 The **AI Lab – Transformers CLI Playground** allows you to explore multiple natural language processing tasks directly from the terminal.  
-Each task (e.g., sentiment, NER, text generation) is implemented as a **Command Module**, which interacts with a **Pipeline Module** built on top of the `transformers` library.
+Each task (e.g., sentiment, NER, text generation, question answering) is implemented as a **Command Module**, which interacts with a **Pipeline Module** built on top of the `transformers` library.
 
 The lab is intentionally structured to demonstrate **clean software design for ML codebases** — with strict separation between configuration, pipelines, CLI logic, and display formatting.
 
@@ -32,7 +32,8 @@ src/
 │   ├── fillmask.py         # Masked token prediction command
 │   ├── textgen.py          # Text generation command
 │   ├── ner.py              # Named Entity Recognition command
-│   └── moderation.py       # Toxicity / content moderation command
+│   ├── moderation.py       # Toxicity / content moderation command
+│   └── qa.py               # Question Answering command
 │
 ├── pipelines/              # Machine learning logic (Hugging Face Transformers)
 │   ├── __init__.py
@@ -41,7 +42,8 @@ src/
 │   ├── fillmask.py
 │   ├── textgen.py
 │   ├── ner.py
-│   └── moderation.py
+│   ├── moderation.py
+│   └── qa.py               # Question Answering pipeline
 │
 └── config/
     ├── __init__.py
@@ -104,7 +106,7 @@ python -m src.main
 poetry run python src/main.py
 ```
 
-You’ll see an interactive menu listing the available commands:
+You'll see an interactive menu listing the available commands:
 
 ```
 Welcome to AI Lab - Transformers CLI Playground
@@ -114,6 +116,7 @@ Available commands:
   • textgen       – Generate text from a prompt
   • ner           – Extract named entities from text
   • moderation    – Detect toxic or unsafe content
+  • qa            – Question Answering on given text context
 ```
 
 ### Example Sessions
@@ -152,6 +155,14 @@ Available commands:
   - California (LOC)
 ```
 
+#### 🔹 Question Answering
+
+```text
+💬 Context: Albert Einstein was born in 1879 in Germany. He developed the theory of relativity.
+❓ Question: When was Einstein born?
+→ Answer: 1879 (confidence: 0.95)
+```
+
 #### 🔹 Moderation
 
 ```text
@@ -173,13 +184,13 @@ The internal structure follows a clean **Command ↔ Pipeline ↔ Display** patt
                       │
                       ▼
              ┌─────────────────┐
-             │   Command Layer │  ← e.g. sentiment.py
+             │   Command Layer │  ← e.g. sentiment.py, qa.py
              │ (user commands) │
              └───────┬─────────┘
                      │
                      ▼
              ┌─────────────────┐
-             │  Pipeline Layer │  ← e.g. pipelines/sentiment.py
+             │  Pipeline Layer │  ← e.g. pipelines/sentiment.py, pipelines/qa.py
              │ (ML logic)      │
              └───────┬─────────┘
                      │
@@ -195,8 +206,8 @@ The internal structure follows a clean **Command ↔ Pipeline ↔ Display** patt
 | Layer        | Description                                                                |
 | ------------ | -------------------------------------------------------------------------- |
 | **CLI**      | Manages user input/output, help menus, and navigation between commands.    |
-| **Command**  | Encapsulates a single user-facing operation (e.g., run sentiment).         |
+| **Command**  | Encapsulates a single user-facing operation (e.g., run sentiment, QA).     |
-| **Pipeline** | Wraps Hugging Face’s `transformers.pipeline()` to perform inference.       |
+| **Pipeline** | Wraps Hugging Face's `transformers.pipeline()` to perform inference.       |
 | **Display**  | Handles clean console rendering (colored output, tables, JSON formatting). |
 | **Config**   | Centralizes model names, limits, and global constants.                     |
 
@@ -215,7 +226,8 @@ class Config:
         "fillmask":  "bert-base-uncased",
         "textgen":   "gpt2",
         "ner":       "dslim/bert-base-NER",
-        "moderation":"unitary/toxic-bert"
+        "moderation":"unitary/toxic-bert",
+        "qa":        "distilbert-base-cased-distilled-squad"
     }
     MAX_LENGTH = 512
     BATCH_SIZE = 8
@@ -260,6 +272,7 @@ Recommended structure:
 tests/
 ├── test_sentiment.py
 ├── test_textgen.py
+├── test_qa.py
 └── ...
 ```
 

src/cli/display.py

@@ -190,3 +190,78 @@ class DisplayFormatter:
                     output.append(f"  • {entity} ({count}x)")
         
         return "\n".join(output)
+    
+    @staticmethod
+    def format_qa_result(result: Dict[str, Any]) -> str:
+        """Format Question Answering result for display"""
+        if "error" in result:
+            return f"❌ {result['error']}"
+        
+        output = []
+        output.append(f"❓ Question: {result['question']}")
+        
+        # Confidence indicator
+        confidence = result['confidence']
+        confidence_emoji = "✅" if result['is_confident'] else "⚠️"
+        confidence_bar = "█" * int(confidence * 10)
+        
+        output.append(f"{confidence_emoji} Answer: {result['answer']}")
+        output.append(f"📊 Confidence: {result['confidence_level']} ({confidence:.1%}) {confidence_bar}")
+        
+        if not result['is_confident']:
+            output.append("⚠️  Low confidence - answer might not be reliable")
+        
+        output.append(f"\n📍 Position: characters {result['start_position']}-{result['end_position']}")
+        output.append(f"📄 Context with answer highlighted:")
+        output.append(f"   {result['highlighted_context']}")
+        
+        return "\n".join(output)
+    
+    @staticmethod
+    def format_qa_context_analysis(analysis: Dict[str, Any]) -> str:
+        """Format QA context analysis for display"""
+        if "error" in analysis:
+            return f"❌ {analysis['error']}"
+        
+        output = []
+        output.append("✅ Context set successfully!")
+        output.append(f"📊 Context Statistics:")
+        
+        stats = analysis['context_stats']
+        output.append(f"   • Words: {stats['word_count']}")
+        output.append(f"   • Sentences: ~{stats['sentence_count']}")
+        output.append(f"   • Characters: {stats['character_count']}")
+        
+        if analysis['suggested_questions']:
+            output.append(f"\n💡 Suggested question types:")
+            for suggestion in analysis['suggested_questions']:
+                output.append(f"   • {suggestion}")
+        
+        if analysis['tips']:
+            output.append(f"\n📝 Tips for good questions:")
+            for tip in analysis['tips']:
+                output.append(f"   • {tip}")
+        
+        return "\n".join(output)
+    
+    @staticmethod
+    def format_qa_multiple_result(result: Dict[str, Any]) -> str:
+        """Format multiple QA results for display"""
+        if "error" in result:
+            return f"❌ {result['error']}"
+        
+        output = []
+        output.append(f"📊 Multiple Questions Analysis")
+        output.append("=" * 50)
+        output.append(f"Total Questions: {result['total_questions']}")
+        output.append(f"Successfully Processed: {result['processed_questions']}")
+        output.append(f"Confident Answers: {result['confident_answers']}")
+        output.append(f"Average Confidence: {result['average_confidence']:.1%}")
+        
+        output.append(f"\n📋 Results:")
+        for qa_result in result['results']:
+            confidence_emoji = "✅" if qa_result['is_confident'] else "⚠️"
+            output.append(f"\n{qa_result['question_number']}. {qa_result['question']}")
+            output.append(f"   {confidence_emoji} {qa_result['answer']} ({qa_result['confidence']:.1%})")
+        
+        return "\n".join(output)

src/commands/__init__.py

@@ -6,5 +6,6 @@ from .fillmask import FillMaskCommand
 from .textgen import TextGenCommand
 from .moderation import ModerationCommand
 from .ner import NERCommand
+from .qa import QACommand
 
-__all__ = ['SentimentCommand', 'FillMaskCommand', 'TextGenCommand', 'ModerationCommand', 'NERCommand']
+__all__ = ['SentimentCommand', 'FillMaskCommand', 'TextGenCommand', 'ModerationCommand', 'NERCommand', 'QACommand']

src/commands/qa.py

@@ -0,0 +1,214 @@
+from src.cli.base import CLICommand
+from src.cli.display import DisplayFormatter
+from src.pipelines.qa import QuestionAnsweringSystem
+
+
+class QACommand(CLICommand):
+    """Interactive Question Answering command"""
+    
+    def __init__(self):
+        self.qa_system = None
+        self.current_context = None
+        self.session_questions = []
+    
+    @property
+    def name(self) -> str:
+        return "qa"
+    
+    @property
+    def description(self) -> str:
+        return "Question Answering - Ask questions about a given text"
+    
+    def _initialize_qa_system(self):
+        """Lazy initialization of the QA system"""
+        if self.qa_system is None:
+            print("🔄 Loading Question Answering model...")
+            self.qa_system = QuestionAnsweringSystem()
+            DisplayFormatter.show_success("QA model loaded!")
+    
+    def _show_instructions(self):
+        """Show usage instructions and examples"""
+        print("\n❓ Question Answering System")
+        print("Ask questions about a text context and get precise answers.")
+        print("\n📝 How it works:")
+        print("  1. First, provide a context (text containing information)")
+        print("  2. Then ask questions about that context")
+        print("  3. The system extracts answers directly from the text")
+        print("\n💡 Example context:")
+        print("  'Albert Einstein was born in 1879 in Germany. He developed the theory of relativity.'")
+        print("💡 Example questions:")
+        print("  - When was Einstein born?")
+        print("  - Where was Einstein born?")
+        print("  - What theory did Einstein develop?")
+        print("\n🎛️  Commands:")
+        print("  'back' - Return to main menu")
+        print("  'help' - Show these instructions")
+        print("  'context' - Set new context")
+        print("  'multi' - Ask multiple questions at once")
+        print("  'session' - Review session history")
+        print("  'settings' - Adjust confidence threshold")
+        print("-" * 70)
+    
+    def _set_context(self):
+        """Allow user to set or change the context"""
+        print("\n📄 Set Context")
+        print("Enter the text that will serve as context for your questions.")
+        print("You can enter multiple lines. Type 'done' when finished.")
+        print("-" * 50)
+        
+        lines = []
+        while True:
+            line = input("📝 ").strip()
+            if line.lower() == 'done':
+                break
+            if line:
+                lines.append(line)
+        
+        if not lines:
+            DisplayFormatter.show_warning("No context provided")
+            return False
+        
+        self.current_context = " ".join(lines)
+        
+        # Analyze context
+        analysis = self.qa_system.interactive_qa(self.current_context)
+        if "error" in analysis:
+            DisplayFormatter.show_error(analysis["error"])
+            return False
+        
+        formatted_analysis = DisplayFormatter.format_qa_context_analysis(analysis)
+        print(formatted_analysis)
+        
+        return True
+    
+    def _ask_single_question(self):
+        """Ask a single question about the current context"""
+        if not self.current_context:
+            DisplayFormatter.show_warning("Please set a context first using 'context' command")
+            return
+        
+        question = input("\n❓ Your question: ").strip()
+        
+        if not question:
+            DisplayFormatter.show_warning("Please enter a question")
+            return
+        
+        DisplayFormatter.show_loading("Finding answer...")
+        result = self.qa_system.answer(question, self.current_context)
+        
+        if "error" not in result:
+            self.session_questions.append(result)
+        
+        formatted_result = DisplayFormatter.format_qa_result(result)
+        print(formatted_result)
+    
+    def _multi_question_mode(self):
+        """Allow asking multiple questions at once"""
+        if not self.current_context:
+            DisplayFormatter.show_warning("Please set a context first using 'context' command")
+            return
+        
+        print("\n❓ Multiple Questions Mode")
+        print("Enter your questions one by one. Type 'done' when finished.")
+        print("-" * 50)
+        
+        questions = []
+        while True:
+            question = input(f"Question #{len(questions)+1}: ").strip()
+            if question.lower() == 'done':
+                break
+            if question:
+                questions.append(question)
+        
+        if not questions:
+            DisplayFormatter.show_warning("No questions provided")
+            return
+        
+        DisplayFormatter.show_loading(f"Processing {len(questions)} questions...")
+        result = self.qa_system.answer_multiple(questions, self.current_context)
+        
+        if "error" not in result:
+            self.session_questions.extend(result["results"])
+        
+        formatted_result = DisplayFormatter.format_qa_multiple_result(result)
+        print(formatted_result)
+    
+    def _show_session_history(self):
+        """Show the history of questions asked in this session"""
+        if not self.session_questions:
+            DisplayFormatter.show_warning("No questions asked in this session yet")
+            return
+        
+        print(f"\n📚 Session History ({len(self.session_questions)} questions)")
+        print("=" * 60)
+        
+        for i, qa in enumerate(self.session_questions, 1):
+            confidence_emoji = "✅" if qa["is_confident"] else "⚠️"
+            print(f"\n{i}. {qa['question']}")
+            print(f"   {confidence_emoji} {qa['answer']} (confidence: {qa['confidence']:.1%})")
+    
+    def _adjust_settings(self):
+        """Allow user to adjust QA settings"""
+        current_threshold = self.qa_system.confidence_threshold
+        print(f"\n⚙️  Current Settings:")
+        print(f"Confidence threshold: {current_threshold:.2f}")
+        print("\nLower threshold = more answers accepted (less strict)")
+        print("Higher threshold = fewer answers accepted (more strict)")
+        
+        try:
+            new_threshold = input(f"Enter new threshold (0.0-1.0, current: {current_threshold}): ").strip()
+            if new_threshold:
+                threshold = float(new_threshold)
+                self.qa_system.set_confidence_threshold(threshold)
+                DisplayFormatter.show_success(f"Threshold set to {threshold:.2f}")
+        except ValueError:
+            DisplayFormatter.show_error("Invalid threshold value")
+    
+    def run(self):
+        """Run interactive Question Answering"""
+        self._initialize_qa_system()
+        self._show_instructions()
+        
+        while True:
+            if self.current_context:
+                context_preview = (self.current_context[:50] + "...") if len(self.current_context) > 50 else self.current_context
+                prompt = f"\n💬 [{context_preview}] Ask a question: "
+            else:
+                prompt = "\n💬 Enter command or set context first: "
+            
+            user_input = input(prompt).strip()
+            
+            if user_input.lower() == 'back':
+                break
+            elif user_input.lower() == 'help':
+                self._show_instructions()
+                continue
+            elif user_input.lower() == 'context':
+                self._set_context()
+                continue
+            elif user_input.lower() == 'multi':
+                self._multi_question_mode()
+                continue
+            elif user_input.lower() == 'session':
+                self._show_session_history()
+                continue
+            elif user_input.lower() == 'settings':
+                self._adjust_settings()
+                continue
+            
+            if not user_input:
+                DisplayFormatter.show_warning("Please enter a question or command")
+                continue
+            
+            # If we have a context and user input is not a command, treat it as a question
+            if self.current_context:
+                DisplayFormatter.show_loading("Finding answer...")
+                result = self.qa_system.answer(user_input, self.current_context)
+                
+                if "error" not in result:
+                    self.session_questions.append(result)
+                
+                formatted_result = DisplayFormatter.format_qa_result(result)
+                print(formatted_result)
+            else:
+                DisplayFormatter.show_warning("Please set a context first using 'context' command")

src/config/settings.py

@@ -19,6 +19,7 @@ class Config:
         "textgen": "gpt2",
         "moderation": "unitary/toxic-bert",
         "ner": "dbmdz/bert-large-cased-finetuned-conll03-english",
+        "qa": "distilbert-base-cased-distilled-squad",
     }
     
     # Interface

src/main.py

@@ -13,6 +13,7 @@ from src.commands import (
     FillMaskCommand,
     ModerationCommand,
     NERCommand,
+    QACommand,
     SentimentCommand,
     TextGenCommand,
 )
@@ -31,6 +32,7 @@ def main():
             TextGenCommand,
             ModerationCommand,
             NERCommand,
+            QACommand,
         ]
         for command in commands_to_register:
             cli.register_command(command())

src/pipelines/__init__.py

@@ -6,6 +6,7 @@ from .fillmask import FillMaskAnalyzer
 from .textgen import TextGenerator
 from .moderation import ContentModerator
 from .ner import NamedEntityRecognizer
+from .qa import QuestionAnsweringSystem
 from .template import TemplatePipeline
 
-__all__ = ['SentimentAnalyzer', 'FillMaskAnalyzer', 'TextGenerator', 'ContentModerator', 'NamedEntityRecognizer', 'TemplatePipeline']
+__all__ = ['SentimentAnalyzer', 'FillMaskAnalyzer', 'TextGenerator', 'ContentModerator', 'NamedEntityRecognizer', 'QuestionAnsweringSystem', 'TemplatePipeline']

src/pipelines/qa.py

@@ -0,0 +1,266 @@
+from transformers import pipeline
+from typing import Dict, List, Optional, Tuple
+from src.config import Config
+import re
+
+
+class QuestionAnsweringSystem:
+    """Question Answering system using transformers"""
+    
+    def __init__(self, model_name: Optional[str] = None):
+        """
+        Initialize the question-answering pipeline
+        
+        Args:
+            model_name: Name of the model to use (optional)
+        """
+        self.model_name = model_name or Config.get_model("qa")
+        print(f"Loading Question Answering model: {self.model_name}")
+        self.pipeline = pipeline("question-answering", model=self.model_name)
+        print("QA model loaded successfully!")
+        
+        # Default confidence threshold
+        self.confidence_threshold = 0.1
+    
+    def answer(self, question: str, context: str, max_answer_len: int = 50) -> Dict:
+        """
+        Answer a question based on the given context
+        
+        Args:
+            question: Question to answer
+            context: Context text containing the answer
+            max_answer_len: Maximum length of the answer
+            
+        Returns:
+            Dictionary with answer, score, and position information
+        """
+        if not question.strip():
+            return {"error": "Empty question"}
+        
+        if not context.strip():
+            return {"error": "Empty context"}
+        
+        try:
+            result = self.pipeline(
+                question=question,
+                context=context,
+                max_answer_len=max_answer_len
+            )
+            
+            confidence_level = self._get_confidence_level(result["score"])
+            highlighted_context = self._highlight_answer_in_context(
+                context, result["answer"], result["start"], result["end"]
+            )
+            
+            return {
+                "question": question,
+                "context": context,
+                "answer": result["answer"],
+                "confidence": round(result["score"], 4),
+                "confidence_level": confidence_level,
+                "start_position": result["start"],
+                "end_position": result["end"],
+                "highlighted_context": highlighted_context,
+                "is_confident": result["score"] >= self.confidence_threshold
+            }
+            
+        except Exception as e:
+            return {"error": f"QA processing error: {str(e)}"}
+    
+    def _get_confidence_level(self, score: float) -> str:
+        """
+        Convert numerical score to confidence level
+        
+        Args:
+            score: Confidence score (0-1)
+            
+        Returns:
+            Confidence level description
+        """
+        if score >= 0.8:
+            return "Very High"
+        elif score >= 0.6:
+            return "High"
+        elif score >= 0.4:
+            return "Medium"
+        elif score >= 0.2:
+            return "Low"
+        else:
+            return "Very Low"
+    
+    def _highlight_answer_in_context(self, context: str, answer: str, start: int, end: int) -> str:
+        """
+        Highlight the answer within the context
+        
+        Args:
+            context: Original context
+            answer: Extracted answer
+            start: Start position of answer
+            end: End position of answer
+            
+        Returns:
+            Context with highlighted answer
+        """
+        if start < 0 or end > len(context):
+            return context
+        
+        before = context[:start]
+        highlighted_answer = f"**{answer}**"
+        after = context[end:]
+        
+        return before + highlighted_answer + after
+    
+    def answer_multiple(self, questions: List[str], context: str, max_answer_len: int = 50) -> Dict:
+        """
+        Answer multiple questions for the same context
+        
+        Args:
+            questions: List of questions to answer
+            context: Context text
+            max_answer_len: Maximum length of answers
+            
+        Returns:
+            Dictionary with all answers and summary statistics
+        """
+        if not questions:
+            return {"error": "No questions provided"}
+        
+        if not context.strip():
+            return {"error": "Empty context"}
+        
+        results = []
+        confident_answers = 0
+        total_confidence = 0
+        
+        for i, question in enumerate(questions, 1):
+            result = self.answer(question, context, max_answer_len)
+            
+            if "error" not in result:
+                results.append({
+                    "question_number": i,
+                    **result
+                })
+                
+                if result["is_confident"]:
+                    confident_answers += 1
+                total_confidence += result["confidence"]
+        
+        if not results:
+            return {"error": "No valid questions processed"}
+        
+        average_confidence = total_confidence / len(results) if results else 0
+        
+        return {
+            "context": context,
+            "total_questions": len(questions),
+            "processed_questions": len(results),
+            "confident_answers": confident_answers,
+            "average_confidence": round(average_confidence, 4),
+            "confidence_threshold": self.confidence_threshold,
+            "results": results
+        }
+    
+    def interactive_qa(self, context: str) -> Dict:
+        """
+        Prepare context for interactive Q&A session
+        
+        Args:
+            context: Context text for questions
+            
+        Returns:
+            Context analysis and preparation info
+        """
+        if not context.strip():
+            return {"error": "Empty context"}
+        
+        # Basic context analysis
+        word_count = len(context.split())
+        sentence_count = len([s for s in context.split('.') if s.strip()])
+        char_count = len(context)
+        
+        # Suggest question types based on content
+        suggested_questions = self._generate_question_suggestions(context)
+        
+        return {
+            "context": context,
+            "context_stats": {
+                "word_count": word_count,
+                "sentence_count": sentence_count,
+                "character_count": char_count
+            },
+            "suggested_questions": suggested_questions,
+            "tips": [
+                "Ask specific questions about facts mentioned in the text",
+                "Use question words: Who, What, When, Where, Why, How",
+                "Keep questions clear and focused",
+                "The answer should be present in the provided context"
+            ]
+        }
+    
+    def _generate_question_suggestions(self, context: str) -> List[str]:
+        """
+        Generate suggested questions based on context analysis
+        
+        Args:
+            context: Context text
+            
+        Returns:
+            List of suggested question templates
+        """
+        suggestions = []
+        
+        # Check for common patterns and suggest relevant questions
+        if re.search(r'\b\d{4}\b', context):  # Years
+            suggestions.append("When did [event] happen?")
+        
+        if re.search(r'\b[A-Z][a-z]+ [A-Z][a-z]+\b', context):  # Names
+            suggestions.append("Who is [person name]?")
+        
+        if re.search(r'\b(founded|created|established|built)\b', context, re.IGNORECASE):
+            suggestions.append("Who founded/created [organization]?")
+        
+        if re.search(r'\b(located|situated|based)\b', context, re.IGNORECASE):
+            suggestions.append("Where is [place/organization] located?")
+        
+        if re.search(r'\b(because|due to|reason)\b', context, re.IGNORECASE):
+            suggestions.append("Why did [event] happen?")
+        
+        if re.search(r'\b(how|method|process)\b', context, re.IGNORECASE):
+            suggestions.append("How does [process] work?")
+        
+        if not suggestions:
+            suggestions = [
+                "What is the main topic of this text?",
+                "Who are the key people mentioned?",
+                "What important events are described?"
+            ]
+        
+        return suggestions[:5]  # Limit to 5 suggestions
+    
+    def set_confidence_threshold(self, threshold: float):
+        """
+        Set the confidence threshold for answers
+        
+        Args:
+            threshold: Threshold between 0 and 1
+        """
+        if 0 <= threshold <= 1:
+            self.confidence_threshold = threshold
+        else:
+            raise ValueError("Threshold must be between 0 and 1")
+    
+    def answer_batch(self, qa_pairs: List[Tuple[str, str]], max_answer_len: int = 50) -> List[Dict]:
+        """
+        Process multiple question-context pairs
+        
+        Args:
+            qa_pairs: List of (question, context) tuples
+            max_answer_len: Maximum length of answers
+            
+        Returns:
+            List of QA results
+        """
+        return [
+            self.answer(question, context, max_answer_len) 
+            for question, context in qa_pairs
+        ]