Update csv_student_dal.py

student/dal/csv_student_dal.py

@@ -50,20 +50,20 @@ class CsvStudentDAL(IStudentDAL):
 
     def _row_to_student(self, row: dict) -> Student:
         """将CSV行数据转换为Student对象"""
-        # 处理日期类型
+        # 处理日期类型，将字符串转换为datetime.date对象
         enrollment_date = row['enrollment_date']
         if enrollment_date:
             enrollment_date = datetime.strptime(enrollment_date, '%Y-%m-%d').date()
 
-        # 处理布尔类型
+        # 处理布尔类型，将字符串转换为布尔值
         gender = row['gender']
         if gender:
             gender = gender.lower() == 'true'
 
-        # 处理数值类型
+        # 处理数值类型，将字符串转换为数值
         height = int(row['height']) if row['height'] else None
         weight = float(row['weight']) if row['weight'] else None
-
+        # 创建并返回学生对象
         return Student(
             name=row['name'],
             id_card=row['id_card'],
@@ -110,64 +110,75 @@ class CsvStudentDAL(IStudentDAL):
         # 检查学号和身份证号是否已存在
         if self.get_by_id(student.id_card) or self.get_by_stu_id(student.stu_id):
             return False
-
+        # 将学生信息追加到CSV文件
         with open(self.file_path, 'a', encoding='utf-8', newline='') as file:
             writer = csv.DictWriter(file, fieldnames=self.headers)
             writer.writerow(self._student_to_row(student))
         return True
 
     def update(self, student: Student) -> bool:
-        """更新学生信息"""
-        students = self.get_all()
+        """
+        更新学生信息
+        通过身份证号匹配要更新的记录
+        """
+        students = self.get_all() # 获取所有学生信息
         updated = False
 
+        # 重写整个CSV文件，替换匹配的学生记录
         with open(self.file_path, 'w', encoding='utf-8', newline='') as file:
             writer = csv.DictWriter(file, fieldnames=self.headers)
-            writer.writeheader()
+            writer.writeheader()# 写入表头
 
             for s in students:
-                if s.id_card == student.id_card:
+                if s.id_card == student.id_card:  # 找到匹配的学生记录
                     writer.writerow(self._student_to_row(student))
                     updated = True
                 else:
-                    writer.writerow(self._student_to_row(s))
+                    writer.writerow(self._student_to_row(s)) # 保持原有记录不变
 
         return updated
 
     def delete_by_id(self, id_card: str) -> bool:
-        """根据身份证号删除学生信息"""
-        students = self.get_all()
+        """
+        根据身份证号删除学生信息
+        通过重写整个文件排除要删除的记录
+        """
+        students = self.get_all()  # 获取所有学生信息
         deleted = False
 
+        # 重写整个CSV文件，排除要删除的学生记录
         with open(self.file_path, 'w', encoding='utf-8', newline='') as file:
             writer = csv.DictWriter(file, fieldnames=self.headers)
-            writer.writeheader()
+            writer.writeheader()  # 写入表头
 
             for s in students:
-                if s.id_card == id_card:
-                    deleted = True
+                if s.id_card == id_card:  # 找到匹配的学生记录
+                    deleted = True  # 标记已删除
                 else:
-                    writer.writerow(self._student_to_row(s))
+                    writer.writerow(self._student_to_row(s))  # 保留其他记录
 
         return deleted
 
     def delete_by_stu_id(self, stu_id: str) -> bool:
-        """根据学号删除学生信息"""
-        students = self.get_all()
+        """
+        根据学号删除学生信息
+        通过重写整个文件排除要删除的记录
+        """
+        students = self.get_all()  # 获取所有学生信息
         deleted = False
 
+        # 重写整个CSV文件，排除要删除的学生记录
         with open(self.file_path, 'w', encoding='utf-8', newline='') as file:
             writer = csv.DictWriter(file, fieldnames=self.headers)
-            writer.writeheader()
+            writer.writeheader()  # 写入表头
 
             for s in students:
-                if s.stu_id == stu_id:
-                    deleted = True
+                if s.stu_id == stu_id:  # 找到匹配的学生记录
+                    deleted = True  # 标记已删除
                 else:
-                    writer.writerow(self._student_to_row(s))
+                    writer.writerow(self._student_to_row(s))  # 保留其他记录
 
         return deleted
-
     def search_by_name(self, name: str) -> List[Student]:
         """根据姓名模糊查询学生信息"""
         return [s for s in self.get_all() if name in s.name]