initial commit

venv/Lib/site-packages/langchain_classic/agents/loading.py

@@ -0,0 +1,148 @@
+"""Functionality for loading agents."""
+
+import json
+import logging
+from pathlib import Path
+from typing import Any
+
+import yaml
+from langchain_core._api import deprecated
+from langchain_core.language_models import BaseLanguageModel
+from langchain_core.tools import Tool
+
+from langchain_classic.agents.agent import BaseMultiActionAgent, BaseSingleActionAgent
+from langchain_classic.agents.types import AGENT_TO_CLASS
+from langchain_classic.chains.loading import load_chain, load_chain_from_config
+
+logger = logging.getLogger(__name__)
+
+URL_BASE = "https://raw.githubusercontent.com/hwchase17/langchain-hub/master/agents/"
+
+
+def _load_agent_from_tools(
+    config: dict,
+    llm: BaseLanguageModel,
+    tools: list[Tool],
+    **kwargs: Any,
+) -> BaseSingleActionAgent | BaseMultiActionAgent:
+    config_type = config.pop("_type")
+    if config_type not in AGENT_TO_CLASS:
+        msg = f"Loading {config_type} agent not supported"
+        raise ValueError(msg)
+
+    agent_cls = AGENT_TO_CLASS[config_type]
+    combined_config = {**config, **kwargs}
+    return agent_cls.from_llm_and_tools(llm, tools, **combined_config)
+
+
+@deprecated("0.1.0", removal="1.0")
+def load_agent_from_config(
+    config: dict,
+    llm: BaseLanguageModel | None = None,
+    tools: list[Tool] | None = None,
+    **kwargs: Any,
+) -> BaseSingleActionAgent | BaseMultiActionAgent:
+    """Load agent from Config Dict.
+
+    Args:
+        config: Config dict to load agent from.
+        llm: Language model to use as the agent.
+        tools: List of tools this agent has access to.
+        kwargs: Additional keyword arguments passed to the agent executor.
+
+    Returns:
+        An agent executor.
+
+    Raises:
+        ValueError: If agent type is not specified in the config.
+    """
+    if "_type" not in config:
+        msg = "Must specify an agent Type in config"
+        raise ValueError(msg)
+    load_from_tools = config.pop("load_from_llm_and_tools", False)
+    if load_from_tools:
+        if llm is None:
+            msg = (
+                "If `load_from_llm_and_tools` is set to True, then LLM must be provided"
+            )
+            raise ValueError(msg)
+        if tools is None:
+            msg = (
+                "If `load_from_llm_and_tools` is set to True, "
+                "then tools must be provided"
+            )
+            raise ValueError(msg)
+        return _load_agent_from_tools(config, llm, tools, **kwargs)
+    config_type = config.pop("_type")
+
+    if config_type not in AGENT_TO_CLASS:
+        msg = f"Loading {config_type} agent not supported"
+        raise ValueError(msg)
+
+    agent_cls = AGENT_TO_CLASS[config_type]
+    if "llm_chain" in config:
+        config["llm_chain"] = load_chain_from_config(config.pop("llm_chain"))
+    elif "llm_chain_path" in config:
+        config["llm_chain"] = load_chain(config.pop("llm_chain_path"))
+    else:
+        msg = "One of `llm_chain` and `llm_chain_path` should be specified."
+        raise ValueError(msg)
+    if "output_parser" in config:
+        logger.warning(
+            "Currently loading output parsers on agent is not supported, "
+            "will just use the default one.",
+        )
+        del config["output_parser"]
+
+    combined_config = {**config, **kwargs}
+    return agent_cls(**combined_config)
+
+
+@deprecated("0.1.0", removal="1.0")
+def load_agent(
+    path: str | Path,
+    **kwargs: Any,
+) -> BaseSingleActionAgent | BaseMultiActionAgent:
+    """Unified method for loading an agent from LangChainHub or local fs.
+
+    Args:
+        path: Path to the agent file.
+        kwargs: Additional keyword arguments passed to the agent executor.
+
+    Returns:
+        An agent executor.
+
+    Raises:
+        RuntimeError: If loading from the deprecated github-based
+            Hub is attempted.
+    """
+    if isinstance(path, str) and path.startswith("lc://"):
+        msg = (
+            "Loading from the deprecated github-based Hub is no longer supported. "
+            "Please use the new LangChain Hub at https://smith.langchain.com/hub "
+            "instead."
+        )
+        raise RuntimeError(msg)
+    return _load_agent_from_file(path, **kwargs)
+
+
+def _load_agent_from_file(
+    file: str | Path,
+    **kwargs: Any,
+) -> BaseSingleActionAgent | BaseMultiActionAgent:
+    """Load agent from file."""
+    valid_suffixes = {"json", "yaml"}
+    # Convert file to Path object.
+    file_path = Path(file) if isinstance(file, str) else file
+    # Load from either json or yaml.
+    if file_path.suffix[1:] == "json":
+        with file_path.open() as f:
+            config = json.load(f)
+    elif file_path.suffix[1:] == "yaml":
+        with file_path.open() as f:
+            config = yaml.safe_load(f)
+    else:
+        msg = f"Unsupported file type, must be one of {valid_suffixes}."
+        raise ValueError(msg)
+    # Load the agent from the config now.
+    return load_agent_from_config(config, **kwargs)