refactor regions

src/classes/essence.py

@@ -1,4 +1,5 @@
 from enum import Enum
+from collections import defaultdict
 
 
 class EssenceType(Enum):
@@ -14,6 +15,32 @@ class EssenceType(Enum):
     def __str__(self) -> str:
         """返回灵气类型的中文名称"""
         return essence_names.get(self, self.value)
+    
+    @classmethod
+    def from_str(cls, essence_str: str) -> 'EssenceType':
+        """
+        从字符串创建EssenceType实例
+        
+        Args:
+            essence_str: 灵气的字符串表示，如 "金", "木", "水", "火", "土"
+            
+        Returns:
+            对应的EssenceType枚举值
+            
+        Raises:
+            ValueError: 如果字符串不匹配任何已知的灵气类型
+        """
+        # 首先尝试匹配中文名称
+        for essence_type, chinese_name in essence_names.items():
+            if chinese_name == essence_str:
+                return essence_type
+        
+        # 然后尝试匹配英文值
+        for essence_type in cls:
+            if essence_type.value == essence_str:
+                return essence_type
+                
+        raise ValueError(f"Unknown essence type: {essence_str}")
 
 essence_names = {
     EssenceType.GOLD: "金",
@@ -31,7 +58,9 @@ class Essence():
     浓度从0~10。
     """
     def __init__(self, density: dict[EssenceType, int]):
-        self.density = density
+        self.density = defaultdict(int)
+        for essence_type, density in density.items():
+            self.density[essence_type] = density
 
     def get_density(self, essence_type: EssenceType) -> int:
         return self.density[essence_type]