Changes: Remove tqdm, Add Custom Pip-Style Progress Bar

Summary

Removed dependency on tqdm library and implemented a custom pip-style training progress bar using only standard Python libraries (sys, time, threading).

Files Modified

train_road_anomaly_model.py

Changes Made

1. Removed Imports (Line 1-30)

Before:

from rich.progress import (...)
from tqdm import tqdm

After:

import threading
import time

2. Custom Progress Bar Implementation (Line 386-462)

Replaced tqdm-based progress rendering with custom _render_progress() function that:

Displays real-time progress with visual bar:

training: 45.0%|█████████░░░░░░░░░░░░| 45/100 [00:30<00:40, 1.37 epoch/s] loss=0.3421 24.50img/s

Components:
- Percentage: 45.0%
- Visual progress bar: █████████░░░░░░░░░░░░ (30 char width)
- Completed/Total: 45/100
- Time: [elapsed<remaining, rate]
- Training stats: loss and speed (img/s)
Features:
- ETA calculation based on per-epoch timing
- 500ms update interval (smooth without excessive output)
- Time formatting: MM:SS or HH:MM:SS
- Final progress line includes newline for clean finish

Benefits

✅ Zero external dependencies - no tqdm, rich, or other progress bar libraries
✅ Lightweight - uses only standard library
✅ Pip-style format - familiar to Python developers
✅ Real-time stats - displays loss and speed alongside progress
✅ ETA calculation - estimates remaining time
✅ Threading-safe - background thread updates don't block training

Example Output

training:  0.0%|░░░░░░░░░░░░░░░░░░░░░░░░░░░░| 0/100 [00:00<00:40, 0.00 epoch/s] loss=0.5000 24.50img/s
training: 10.0%|███░░░░░░░░░░░░░░░░░░░░░░░░░| 10/100 [00:10<00:35, 1.00 epoch/s] loss=0.4700 24.50img/s
training: 20.0%|██████░░░░░░░░░░░░░░░░░░░░░░| 20/100 [00:20<00:30, 1.00 epoch/s] loss=0.4400 24.50img/s
...
training:100.0%|██████████████████████████████| 100/100 [00:50<00:00, 2.00 epoch/s] loss=0.2000 24.50img/s

Usage

No changes needed - progress bar appears automatically during training via background thread.

Testing

Demo script created: demo_progress_bar.py demonstrates the progress bar output format.