shared base for file IO manager

apps/weather/src/resources.py

@@ -0,0 +1,37 @@
+import json
+from typing import Any
+
+from shared.resources import BaseIOManager
+from upath import UPath
+
+import dagster as dg
+
+
+def _process_env_vars(config: dict[str, Any]) -> dict[str, Any]:
+    out = {}
+    for key, value in config.items():
+        if (
+            isinstance(value, dict)
+            and len(value) == 1
+            and next(iter(value.keys())) == "env"
+        ):
+            out[key] = dg.EnvVar(next(iter(value.values()))).get_value()
+        else:
+            out[key] = value
+    return out
+
+
+class JsonIOManager(BaseIOManager):
+    extension: str = ".json"  # Automatically adds a .json extension
+
+    def dump_to_path(
+        self, context: dg.OutputContext, obj: object, path: "UPath"
+    ) -> None:
+        """This saves the output of an asset to a file path."""
+        with path.open("w") as fp:
+            json.dump(obj, fp, indent=4)
+
+    def load_from_path(self, context: dg.InputContext, path: "UPath") -> object:
+        """This loads an input for a downstream asset from a file path."""
+        with path.open("r") as fp:
+            return json.load(fp)

shared/src/shared/resources.py

@@ -1,4 +1,5 @@
 import json
+from abc import ABC, abstractmethod
 from typing import Any
 
 from pydantic import Field, PrivateAttr
@@ -21,13 +22,8 @@ def _process_env_vars(config: dict[str, Any]) -> dict[str, Any]:
     return out
 
 
-class JsonIOManager(dg.ConfigurableIOManager, dg.UPathIOManager):
+class BaseIOManager(dg.ConfigurableIOManager, dg.UPathIOManager, ABC):
-    """
+    extension: str
-    An I/O manager that stores data as JSON files. It inherits from
-    UPathIOManager, which handles path creation for local/cloud storage.
-    """
-
-    extension: str = ".json"  # Automatically adds a .json extension
     base_dir: str | None = Field(
         default=None, description="Base directory for storing files."
     )
@@ -50,6 +46,7 @@ class JsonIOManager(dg.ConfigurableIOManager, dg.UPathIOManager):
             else UPath(dg._check.not_none(context.instance).storage_directory())
         )
 
+    @abstractmethod
     def dump_to_path(
         self, context: dg.OutputContext, obj: object, path: "UPath"
     ) -> None:
@@ -57,6 +54,7 @@ class JsonIOManager(dg.ConfigurableIOManager, dg.UPathIOManager):
         with path.open("w") as fp:
             json.dump(obj, fp, indent=4)
 
+    @abstractmethod
     def load_from_path(self, context: dg.InputContext, path: "UPath") -> object:
         """This loads an input for a downstream asset from a file path."""
         with path.open("r") as fp: