fix : replace deprecated datetime.utcnow with timezone-aware alternative in code_review

src/utils/certification.py

@@ -1,7 +1,7 @@
 """Learning outcome assessment and certification system."""
 
 from typing import Dict, List, Optional
-from datetime import datetime
+from datetime import datetime, timezone
 import hashlib
 
 
@@ -28,7 +28,7 @@ def create_assessment(
             "skill": skill,
             "difficulty": difficulty,
             "questions": questions,
-            "created_at": datetime.utcnow().isoformat(),
+            "created_at": datetime.now(timezone.utc).isoformat(),
             "score": None,
             "passed": False,
             "completed_at": None,
@@ -48,7 +48,7 @@ def submit_assessment(
 
         assessment["score"] = score
         assessment["passed"] = score >= 70
-        assessment["completed_at"] = datetime.utcnow().isoformat()
+        assessment["completed_at"] = datetime.now(timezone.utc).isoformat()
 
         if assessment["passed"]:
             self._issue_certificate(assessment)
@@ -77,7 +77,7 @@ def _issue_certificate(self, assessment: Dict):
             "skill": assessment["skill"],
             "difficulty": assessment["difficulty"],
             "score": assessment["score"],
-            "issued_at": datetime.utcnow().isoformat(),
+            "issued_at": datetime.now(timezone.utc).isoformat(),
             "valid_until": None,
             "verification_code": self._generate_verification_code(cert_id),
         }
@@ -86,7 +86,7 @@ def _issue_certificate(self, assessment: Dict):
 
     def _generate_verification_code(self, cert_id: str) -> str:
         """Generate unique verification code."""
-        data = f"{cert_id}{datetime.utcnow().isoformat()}".encode()
+        data = f"{cert_id}{datetime.now(timezone.utc).isoformat()}".encode()
         return hashlib.sha256(data).hexdigest()[:16]
 
     def issue_digital_badge(self, user_id: str, skill: str, level: str) -> Dict:
@@ -97,7 +97,7 @@ def issue_digital_badge(self, user_id: str, skill: str, level: str) -> Dict:
             "user_id": user_id,
             "skill": skill,
             "level": level,
-            "issued_at": datetime.utcnow().isoformat(),
+            "issued_at": datetime.now(timezone.utc).isoformat(),
             "icon_url": f"/badges/{skill.lower()}_{level.lower()}.png",
             "description": f"{level} {skill} Badge",
         }

src/utils/code_review.py

@@ -7,7 +7,7 @@
 
 from typing import Dict, List, Optional
 from enum import Enum
-from datetime import datetime
+from datetime import datetime, timezone
 
 
 class ReviewStatus(Enum):
@@ -100,7 +100,7 @@ def submit_code(
             "code": code,
             "language": language,
             "description": description or "",
-            "submitted_at": datetime.utcnow().isoformat(),
+            "submitted_at": datetime.now(timezone.utc).isoformat(),
             "review_status": ReviewStatus.PENDING.value,
             "review_count": 0,
             "metrics": {},
@@ -128,13 +128,13 @@ def start_review(
             raise ValueError(f"Submission {submission_id} not found")
 
         submission = self.submissions[submission_id]
-        review_id = f"review_{submission_id}_{datetime.utcnow().timestamp()}"
+        review_id = f"review_{submission_id}_{datetime.now(timezone.utc).timestamp()}"
 
         review = {
             "review_id": review_id,
             "submission_id": submission_id,
             "reviewer_id": reviewer_id,
-            "started_at": datetime.utcnow().isoformat(),
+            "started_at": datetime.now(timezone.utc).isoformat(),
             "completed_at": None,
             "status": ReviewStatus.IN_PROGRESS.value,
             "overall_score": None,
@@ -178,7 +178,7 @@ def add_feedback_comment(
             "code_snippet": code_snippet,
             "feedback": feedback,
             "severity": severity,
-            "created_at": datetime.utcnow().isoformat(),
+            "created_at": datetime.now(timezone.utc).isoformat(),
         }
 
         self.feedback_comments[review_id].append(comment)
@@ -249,7 +249,7 @@ def complete_review(
         scores = [s["score"] for s in review["category_scores"].values()]
         overall_score = sum(scores) / len(scores) if scores else 0
 
-        review["completed_at"] = datetime.utcnow().isoformat()
+        review["completed_at"] = datetime.now(timezone.utc).isoformat()
         review["overall_score"] = round(overall_score, 2)
         review["summary"] = summary
         review["status"] = (