Update project structure and enhance model persistence

- Added new model and scaler files to .gitignore and output directory.
- Updated Dockerfile to create output/models directory.
- Revised README to include instructions for using a .env file for configuration.
- Enhanced config.py to load database credentials from environment variables.
- Implemented model saving functionality in salary_predictor.py for consistent and inconsistent earners.

README.md

@@ -21,6 +21,7 @@ A comprehensive salary analytics system that analyzes transaction data to identi
   - Separate models for consistent and inconsistent earners
   - Feature engineering
   - Model evaluation metrics
+  - Model persistence (saved in output/models)
 
 - **Reporting**
   - CSV reports generation
@@ -48,25 +49,20 @@ salary_analytics/
 
 ## Configuration
 
-The system can be configured through environment variables or the `config.py` file:
+The system can be configured through environment variables using a `.env` file:
 
-```python
-# Database Configuration
-DB_CONFIG = {
-    "user": "db_user",
-    "password": "your_secure_password",
-    "name": "salary_db",
-    "port": "5432",
-    "host": "localhost"
-}
+1. Copy the example environment file:
+```bash
+cp .env.example .env
+```
 
-# Model Configuration
-MODEL_CONFIG = {
-    "cv_threshold": 0.10,
-    "min_transactions": 3,
-    "threshold": 0.7,
-    "high_earner_threshold": 10000
-}
+2. Edit the `.env` file with your database credentials:
+```bash
+DB_USER=your_username
+DB_PASSWORD=your_password
+DB_NAME=your_database
+DB_PORT=your_port
+DB_HOST=your_host
 ```
 
 ## Usage
@@ -140,9 +136,15 @@ Note: All analysis endpoints require data to be loaded first. If you try to run
 docker-compose build
 ```
 
-2. Run the container:
+2. Run the container with environment variables:
 ```bash
-docker-compose up
+docker run -v $(pwd)/output:/app/output \
+           -e DB_USER=your_username \
+           -e DB_PASSWORD=your_password \
+           -e DB_NAME=your_database \
+           -e DB_PORT=your_port \
+           -e DB_HOST=your_host \
+           salary-analytics
 ```
 
 The API will be available at http://localhost:8000
@@ -155,8 +157,13 @@ output/
 │   ├── high_earner_details.csv
 │   ├── likely_salary_earner.csv
 │   └── final_table.csv
-└── plots/
-    ├── consistent_earners_predictions.png
-    ├── inconsistent_earners_predictions.png
-    └── hypothesis_overlap.png
+├── plots/
+│   ├── consistent_earners_predictions.png
+│   ├── inconsistent_earners_predictions.png
+│   └── hypothesis_overlap.png
+└── models/
+    ├── consistent_model.joblib
+    ├── inconsistent_model.joblib
+    ├── consistent_scaler.joblib
+    └── inconsistent_scaler.joblib
 ```