Add Week 9 XGBoost pipeline and evidence (Shashank Samyal)

[SHASHANKVAMP]

This PR contains my individual contribution for Week 7–9 (Shashank Samyal).

Summary

Adds my Week 7–9 ML contribution for the Lachesis “Wearables for Seniors” project:

• Preprocessing with privacy-preserving features (Age bands, BMI handling)
• XGBoost training + evaluation pipeline (reproducible notebooks + scripts)
• Saved artifacts (metrics, confusion matrix, feature importances, predictions)

Included

• notebooks/: pre_processing.ipynb, week9_xgboost.ipynb
• outputs/: classification_report.csv, confusion_matrix.csv/png, cv_scores.csv,
  feature_importances.csv/png, summary_metrics.csv, label_classes.csv, predictions.csv
• data/: Final_combined_dataset.csv, legality_ethics_audit_findings.csv, obesity.csv
• reports/: Obesity_Model_Report.pdf, Geospatial_Tools_Research.pdf
• scripts/: childhood_obesity_ml.py, run_obesity_model.py

Evidence

Accuracy: 0.8585
CV Mean Accuracy: 0.8665 (±0.0073)
Classes: 7, Features: 25

Author

Shashank Samyal — Week 7–9 pipeline & documentation.

[github-actions]

🔒 Security Scan Results

🔒 Security Scan Results
=========================

Bandit Scan Results:
-------------------
Run started:2025-09-24 15:32:54.505546

Test results:
>> Issue: [B101:assert_used] Use of assert detected. The enclosed code will be removed when compiling to optimised byte code.
   Severity: Low   Confidence: High
   CWE: CWE-703 (https://cwe.mitre.org/data/definitions/703.html)
   More Info: https://bandit.readthedocs.io/en/1.8.6/plugins/b101_assert_used.html
   Location: ./data_science/shashank_week9_xgboost/scripts/run_obesity_model.py:14:0
13	TARGET = "NObeyesdad"  # e.g., Normal_Weight, Overweight_Level_I, Obesity_Type_I, ...
14	assert TARGET in df.columns, f"{TARGET} not found. Columns: {list(df.columns)}"
15	

--------------------------------------------------
>> Issue: [B113:request_without_timeout] Call to requests without timeout
   Severity: Medium   Confidence: Low
   CWE: CWE-400 (https://cwe.mitre.org/data/definitions/400.html)
   More Info: https://bandit.readthedocs.io/en/1.8.6/plugins/b113_request_without_timeout.html
   Location: ./data_science/voice_assistant/generate_response.py:19:10
18	def get_request(query):
19	    req = requests.get(f'https://www.google.com/search?q={query}')
20	

--------------------------------------------------
>> Issue: [B404:blacklist] Consider possible security implications associated with the subprocess module.
   Severity: Low   Confidence: High
   CWE: CWE-78 (https://cwe.mitre.org/data/definitions/78.html)
   More Info: https://bandit.readthedocs.io/en/1.8.6/blacklists/blacklist_imports.html#b404-import-subprocess
   Location: ./data_science/voice_assistant/text_to_speech.py:5:0
4	import os
5	import subprocess
6	# Function to generate a response using our NLP model

--------------------------------------------------
>> Issue: [B607:start_process_with_partial_path] Starting a process with a partial executable path
   Severity: Low   Confidence: High
   CWE: CWE-78 (https://cwe.mitre.org/data/definitions/78.html)
   More Info: https://bandit.readthedocs.io/en/1.8.6/plugins/b607_start_process_with_partial_path.html
   Location: ./data_science/voice_assistant/text_to_speech.py:15:4
14	    time.sleep(2)
15	    subprocess.run(['say', response], check=True)
16	

--------------------------------------------------
>> Issue: [B603:subprocess_without_shell_equals_true] subprocess call - check for execution of untrusted input.
   Severity: Low   Confidence: High
   CWE: CWE-78 (https://cwe.mitre.org/data/definitions/78.html)
   More Info: https://bandit.readthedocs.io/en/1.8.6/plugins/b603_subprocess_without_shell_equals_true.html
   Location: ./data_science/voice_assistant/text_to_speech.py:15:4
14	    time.sleep(2)
15	    subprocess.run(['say', response], check=True)
16	

--------------------------------------------------

Code scanned:
	Total lines of code: 1067
	Total lines skipped (#nosec): 0
	Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 0

Run metrics:
	Total issues (by severity):
		Undefined: 0
		Low: 4
		Medium: 1
		High: 0
	Total issues (by confidence):
		Undefined: 0
		Low: 1
		Medium: 0
		High: 4
Files skipped (0):

✅ No critical security issues detected.

The code has passed all critical security checks.