change symbol to use str object instead of bytes

anansyTypes/structures/symbol.py

@@ -1,6 +1,7 @@
 from dataclasses import dataclass
 from typing import Any
 import numpy as np
+from pydantic import BaseModel
 from pydantic_tensor import Tensor
 from typing import Any, Literal
 from pydantic_core import core_schema
@@ -8,54 +9,7 @@ import base64
 
 
 @dataclass
-class Symbol:
+class Symbol(BaseModel):
     id: int
     label: str
-    image: bytes
-
-    @classmethod
-    def from_dict(cls, data: dict) -> "Symbol":
-        if isinstance(data["image"], str):
-            image_bytes = base64.b64decode(data["image"])
-        else:
-            image_bytes = bytes(data["image"])
-        
-        return cls(
-            id=data["id"],
-            label=data["label"],
-            image=image_bytes,
-        )
-
-    @classmethod
-    def __get_pydantic_core_schema__(cls, source_type: Any, handler):
-        from pydantic_core import core_schema
-
-        def validate_symbol(value):
-            if isinstance(value, cls):
-                return value
-            if isinstance(value, dict):
-                return cls.from_dict(value)
-            raise ValueError(f"Cannot convert {type(value)} to Symbol")
-
-        python_schema = core_schema.with_info_plain_validator_function(
-            lambda value, _: validate_symbol(value),
-            serialization=core_schema.plain_serializer_function_ser_schema(
-                lambda x: {
-                    "id": x.id,
-                    "label": x.label,
-                    "image": base64.b64encode(x.image).decode("utf-8"),
-                },
-                when_used="json",
-            ),
-        )
-
-        return core_schema.json_or_python_schema(
-            json_schema=core_schema.typed_dict_schema(
-                {
-                    "id": core_schema.typed_dict_field(core_schema.int_schema()),
-                    "label": core_schema.typed_dict_field(core_schema.str_schema()),
-                    "image": core_schema.typed_dict_field(core_schema.str_schema()),
-                }
-            ),
-            python_schema=python_schema,
-        )
+    image: str  # Base64-encoded PNG image data