Source code for langchain_community.tools.playwright.base
from __future__ import annotations
from typing import TYPE_CHECKING, Optional, Tuple, Type
from langchain_core.pydantic_v1 import root_validator
from langchain_core.tools import BaseTool
from langchain_core.utils import guard_import
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
[docs]def lazy_import_playwright_browsers() -> Tuple[Type[AsyncBrowser], Type[SyncBrowser]]:
"""
Lazy import playwright browsers.
Returns:
Tuple[Type[AsyncBrowser], Type[SyncBrowser]]:
AsyncBrowser and SyncBrowser classes.
"""
return (
guard_import(module_name="playwright.async_api").Browser,
guard_import(module_name="playwright.sync_api").Browser,
)
[docs]class BaseBrowserTool(BaseTool):
"""Base class for browser tools."""
sync_browser: Optional["SyncBrowser"] = None
async_browser: Optional["AsyncBrowser"] = None
@root_validator(pre=True)
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
[docs] @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) # type: ignore[call-arg]