add backend source code

backend/app/utils/__init__.py

@@ -0,0 +1,33 @@
+"""
+工具函数模块
+"""
+from datetime import datetime
+from typing import Optional
+
+
+def get_current_period() -> tuple[int, int]:
+    """获取当前考核周期（年、月）"""
+    now = datetime.now()
+    return now.year, now.month
+
+
+def format_period(year: int, month: int) -> str:
+    """格式化考核周期"""
+    return f"{year}年{month:02d}月"
+
+
+def calculate_score_level(score: float) -> str:
+    """计算绩效等级"""
+    if score >= 90:
+        return "优秀"
+    elif score >= 80:
+        return "良好"
+    elif score >= 60:
+        return "合格"
+    else:
+        return "不合格"
+
+
+def generate_employee_id(department_code: str, sequence: int) -> str:
+    """生成员工工号"""
+    return f"{department_code}{sequence:04d}"