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langchain/langchain/tools/playwright/base.py

56 lines
1.9 KiB
Python

from __future__ import annotations
from typing import TYPE_CHECKING, Optional, Tuple, Type
from pydantic import root_validator
from langchain.tools.base import BaseTool
if TYPE_CHECKING:
from playwright.async_api import Browser as AsyncBrowser
from playwright.sync_api import Browser as SyncBrowser
else:
try:
# We do this so pydantic can resolve the types when instantiating
from playwright.async_api import Browser as AsyncBrowser
from playwright.sync_api import Browser as SyncBrowser
except ImportError:
pass
def lazy_import_playwright_browsers() -> Tuple[Type[AsyncBrowser], Type[SyncBrowser]]:
try:
from playwright.async_api import Browser as AsyncBrowser # noqa: F401
from playwright.sync_api import Browser as SyncBrowser # noqa: F401
except ImportError:
raise ValueError(
"The 'playwright' package is required to use the playwright tools."
" Please install it with 'pip install playwright'."
)
return AsyncBrowser, SyncBrowser
class BaseBrowserTool(BaseTool):
"""Base class for browser tools."""
sync_browser: Optional["SyncBrowser"] = None
async_browser: Optional["AsyncBrowser"] = None
@root_validator
def validate_browser_provided(cls, values: dict) -> dict:
"""Check that the arguments are valid."""
lazy_import_playwright_browsers()
if values.get("async_browser") is None and values.get("sync_browser") is None:
raise ValueError("Either async_browser or sync_browser must be specified.")
return values
@classmethod
def from_browser(
cls,
sync_browser: Optional[SyncBrowser] = None,
async_browser: Optional[AsyncBrowser] = None,
) -> BaseBrowserTool:
"""Instantiate the tool."""
lazy_import_playwright_browsers()
return cls(sync_browser=sync_browser, async_browser=async_browser)