Harrison/official pre release (#8106)

libs/experimental/langchain_experimental/prompts/__init__.py

@@ -0,0 +1,3 @@
+from langchain_experimental.prompts.load import load_prompt
+
+__all__ = ["load_prompt"]

libs/experimental/langchain_experimental/prompts/load.py

@@ -0,0 +1,51 @@
+# Susceptible to arbitrary code execution: https://github.com/hwchase17/langchain/issues/4849
+import importlib
+import json
+from pathlib import Path
+from typing import Union
+
+import yaml
+from langchain.prompts.loading import load_prompt_from_config, try_load_from_hub
+from langchain.schema.prompts import BasePromptTemplate
+
+
+def load_prompt(path: Union[str, Path]) -> BasePromptTemplate:
+    """Unified method for loading a prompt from LangChainHub or local fs."""
+    if hub_result := try_load_from_hub(
+        path, _load_prompt_from_file, "prompts", {"py", "json", "yaml"}
+    ):
+        return hub_result
+    else:
+        return _load_prompt_from_file(path)
+
+
+def _load_prompt_from_file(file: Union[str, Path]) -> BasePromptTemplate:
+    """Load prompt from file."""
+    # Convert file to a Path object.
+    if isinstance(file, str):
+        file_path = Path(file)
+    else:
+        file_path = file
+    # Load from either json or yaml.
+    if file_path.suffix == ".json":
+        with open(file_path) as f:
+            config = json.load(f)
+    elif file_path.suffix == ".yaml":
+        with open(file_path, "r") as f:
+            config = yaml.safe_load(f)
+    elif file_path.suffix == ".py":
+        spec = importlib.util.spec_from_loader(
+            "prompt", loader=None, origin=str(file_path)
+        )
+        if spec is None:
+            raise ValueError("could not load spec")
+        helper = importlib.util.module_from_spec(spec)
+        with open(file_path, "rb") as f:
+            exec(f.read(), helper.__dict__)
+        if not isinstance(helper.PROMPT, BasePromptTemplate):
+            raise ValueError("Did not get object of type BasePromptTemplate.")
+        return helper.PROMPT
+    else:
+        raise ValueError(f"Got unsupported file type {file_path.suffix}")
+    # Load the prompt from the config now.
+    return load_prompt_from_config(config)