viruPVS/langchain-docs huggingface dataset:
Source code for langchain.chains.hyde.base
"""Hypothetical Document Embeddings.
https://arxiv.org/abs/2212.10496
"""
from __future__ import annotations
from typing import Any, Dict, List, Optional
import numpy as np
from langchain_core.embeddings import Embeddings
from langchain_core.language_models import BaseLanguageModel
from langchain_core.prompts import BasePromptTemplate
from langchain_core.pydantic_v1 import Extra
from langchain.callbacks.manager import CallbackManagerForChainRun
from langchain.chains.base import Chain
from langchain.chains.hyde.prompts import PROMPT_MAP
from langchain.chains.llm import LLMChain
[docs]class HypotheticalDocumentEmbedder(Chain, Embeddings):
    """Generate hypothetical document for query, and then embed that.
    Based on https://arxiv.org/abs/2212.10496
    """
    base_embeddings: Embeddings
    llm_chain: LLMChain
    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
        arbitrary_types_allowed = True
    @property
    def input_keys(self) -> List[str]:
        """Input keys for Hyde's LLM chain."""
        return self.llm_chain.input_keys
    @property
    def output_keys(self) -> List[str]:
        """Output keys for Hyde's LLM chain."""
        return self.llm_chain.output_keys
[docs]    def embed_documents(self, texts: List[str]) -> List[List[float]]:
        """Call the base embeddings."""
        return self.base_embeddings.embed_documents(texts)
[docs]    def combine_embeddings(self, embeddings: List[List[float]]) -> List[float]:
        """Combine embeddings into final embeddings."""
"""Combine embeddings into final embeddings."""
        return list(np.array(embeddings).mean(axis=0))
[docs]    def embed_query(self, text: str) -> List[float]:
        """Generate a hypothetical document and embedded it."""
        var_name = self.llm_chain.input_keys[0]
        result = self.llm_chain.generate([{var_name: text}])
        documents = [generation.text for generation in result.generations[0]]
        embeddings = self.embed_documents(documents)
        return self.combine_embeddings(embeddings)
    def _call(
        self,
        inputs: Dict[str, Any],
        run_manager: Optional[CallbackManagerForChainRun] = None,
    ) -> Dict[str, str]:
        """Call the internal llm chain."""
        _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
        return self.llm_chain(inputs, callbacks=_run_manager.get_child())
[docs]    @classmethod
    def from_llm(
        cls,
        llm: BaseLanguageModel,
        base_embeddings: Embeddings,
        prompt_key: Optional[str] = None,
        custom_prompt: Optional[BasePromptTemplate] = None,
        **kwargs: Any,
    ) -> HypotheticalDocumentEmbedder:
        """Load and use LLMChain with either a specific prompt key or custom prompt."""
        if custom_prompt is not None:
            prompt = custom_prompt
        elif prompt_key is not None and prompt_key in PROMPT_MAP:
            prompt = PROMPT_MAP[prompt_key]
        else:
            raise ValueError(
                f"Must specify prompt_key if custom_prompt not provided. Should be one "
                f"of {list(PROMPT_MAP.keys())}."
            )
Source code for langchain.chains.natbot.base
"""Implement an LLM driven browser."""
from __future__ import annotations
import warnings
from typing import Any, Dict, List, Optional
from langchain_core.language_models import BaseLanguageModel
from langchain_core.pydantic_v1 import Extra, root_validator
from langchain.callbacks.manager import CallbackManagerForChainRun
from langchain.chains.base import Chain
from langchain.chains.llm import LLMChain
from langchain.chains.natbot.prompt import PROMPT
from langchain.llms.openai import OpenAI
[docs]class NatBotChain(Chain):
    """Implement an LLM driven browser.
    **Security Note**: This toolkit provides code to control a web-browser.
        The web-browser can be used to navigate to:
        - Any URL (including any internal network URLs)
        - And local files
        Exercise care if exposing this chain to end-users. Control who is able to
        access and use this chain, and isolate the network access of the server
        that hosts this chain.
        See https://python.langchain.com/docs/security for more information.
    Example:
        .. code-block:: python
            from langchain.chains import NatBotChain
            natbot = NatBotChain.from_default("Buy me a new hat.")
    """
    llm_chain: LLMChain
    objective: str
    """Objective that NatBot is tasked with completing."""
    llm: Optional[BaseLanguageModel] = None
    """[Deprecated] LLM wrapper to use."""
    input_url_key: str = "url"  #: :meta private:
    input_browser_content_key: str = "browser_content"  #: :meta private:
    previous_command: str = ""  #: :meta private:
previous_command: str = ""  #: :meta private:
    output_key: str = "command"  #: :meta private:
    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
        arbitrary_types_allowed = True
    @root_validator(pre=True)
    def raise_deprecation(cls, values: Dict) -> Dict:
        if "llm" in values:
            warnings.warn(
                "Directly instantiating an NatBotChain with an llm is deprecated. "
                "Please instantiate with llm_chain argument or using the from_llm "
                "class method."
            )
            if "llm_chain" not in values and values["llm"] is not None:
                values["llm_chain"] = LLMChain(llm=values["llm"], prompt=PROMPT)
        return values
[docs]    @classmethod
    def from_default(cls, objective: str, **kwargs: Any) -> NatBotChain:
        """Load with default LLMChain."""
        llm = OpenAI(temperature=0.5, best_of=10, n=3, max_tokens=50)
        return cls.from_llm(llm, objective, **kwargs)
[docs]    @classmethod
    def from_llm(
        cls, llm: BaseLanguageModel, objective: str, **kwargs: Any
    ) -> NatBotChain:
        """Load from LLM."""
        llm_chain = LLMChain(llm=llm, prompt=PROMPT)
        return cls(llm_chain=llm_chain, objective=objective, **kwargs)
    @property
    def input_keys(self) -> List[str]:
        """Expect url and browser content.
        :meta private:
        """
"""Expect url and browser content.
        :meta private:
        """
        return [self.input_url_key, self.input_browser_content_key]
    @property
    def output_keys(self) -> List[str]:
        """Return command.
        :meta private:
        """
        return [self.output_key]
    def _call(
        self,
        inputs: Dict[str, str],
        run_manager: Optional[CallbackManagerForChainRun] = None,
    ) -> Dict[str, str]:
        _run_manager = run_manager or CallbackManagerForChainRun.get_noop_manager()
        url = inputs[self.input_url_key]
        browser_content = inputs[self.input_browser_content_key]
        llm_cmd = self.llm_chain.predict(
            objective=self.objective,
            url=url[:100],
            previous_command=self.previous_command,
            browser_content=browser_content[:4500],
            callbacks=_run_manager.get_child(),
        )
        llm_cmd = llm_cmd.strip()
        self.previous_command = llm_cmd
        return {self.output_key: llm_cmd}
[docs]    def execute(self, url: str, browser_content: str) -> str:
        """Figure out next browser command to run.
        Args:
            url: URL of the site currently on.
            browser_content: Content of the page as currently displayed by the browser.
        Returns:
            Next browser command to run.
        Example:
            .. code-block:: python
                browser_content = "...."
                llm_command = natbot.run("www.google.com", browser_content)
        """
        _inputs = {
            self.input_url_key: url,
            self.input_browser_content_key: browser_content,
        }
        return self(_inputs)[self.output_key]
Source code for langchain.chains.natbot.crawler
# flake8: noqa
import time
from sys import platform
from typing import (
    TYPE_CHECKING,
    Any,
    Dict,
    Iterable,
    List,
    Optional,
    Set,
    Tuple,
    TypedDict,
    Union,
)
if TYPE_CHECKING:
    from playwright.sync_api import Browser, CDPSession, Page, sync_playwright
black_listed_elements: Set[str] = {
    "html",
    "head",
    "title",
    "meta",
    "iframe",
    "body",
    "script",
    "style",
    "path",
    "svg",
    "br",
    "::marker",
}
[docs]class ElementInViewPort(TypedDict):
    """A typed dictionary containing information about elements in the viewport."""
    node_index: str
    backend_node_id: int
    node_name: Optional[str]
    node_value: Optional[str]
    node_meta: List[str]
    is_clickable: bool
    origin_x: int
    origin_y: int
    center_x: int
    center_y: int
[docs]class Crawler:
    """A crawler for web pages.
    **Security Note**: This is an implementation of a crawler that uses a browser via
        Playwright.
        This crawler can be used to load arbitrary webpages INCLUDING content
        from the local file system.
        Control access to who can submit crawling requests and what network access
        the crawler has.
        Make sure to scope permissions to the minimal permissions necessary for
        the application.
        See https://python.langchain.com/docs/security for more information.
    """
[docs]    def __init__(self) -> None:
"""
[docs]    def __init__(self) -> None:
        try:
            from playwright.sync_api import sync_playwright
        except ImportError:
            raise ImportError(
                "Could not import playwright python package. "
                "Please install it with `pip install playwright`."
            )
        self.browser: Browser = (
            sync_playwright().start().chromium.launch(headless=False)
        )
        self.page: Page = self.browser.new_page()
        self.page.set_viewport_size({"width": 1280, "height": 1080})
        self.page_element_buffer: Dict[int, ElementInViewPort]
        self.client: CDPSession
[docs]    def go_to_page(self, url: str) -> None:
        self.page.goto(url=url if "://" in url else "http://" + url)
        self.client = self.page.context.new_cdp_session(self.page)
        self.page_element_buffer = {}
[docs]    def scroll(self, direction: str) -> None:
        if direction == "up":
            self.page.evaluate(
                "(document.scrollingElement || document.body).scrollTop = (document.scrollingElement || document.body).scrollTop - window.innerHeight;"
            )
        elif direction == "down":
            self.page.evaluate(
                "(document.scrollingElement || document.body).scrollTop = (document.scrollingElement || document.body).scrollTop + window.innerHeight;"
            )
[docs]    def click(self, id: Union[str, int]) -> None:
        # Inject javascript into the page which removes the target= attribute from all links
        js = """
		links = document.getElementsByTagName("a");
		for (var i = 0; i < links.length; i++) {
			links[i].removeAttribute("target");
		}
links[i].removeAttribute("target");
		}
		"""
        self.page.evaluate(js)
        element = self.page_element_buffer.get(int(id))
        if element:
            x: float = element["center_x"]
            y: float = element["center_y"]
            self.page.mouse.click(x, y)
        else:
            print("Could not find element")
[docs]    def type(self, id: Union[str, int], text: str) -> None:
        self.click(id)
        self.page.keyboard.type(text)
[docs]    def enter(self) -> None:
        self.page.keyboard.press("Enter")
[docs]    def crawl(self) -> List[str]:
        page = self.page
        page_element_buffer = self.page_element_buffer
        start = time.time()
        page_state_as_text = []
        device_pixel_ratio: float = page.evaluate("window.devicePixelRatio")
        if platform == "darwin" and device_pixel_ratio == 1:  # lies
            device_pixel_ratio = 2
        win_upper_bound: float = page.evaluate("window.pageYOffset")
        win_left_bound: float = page.evaluate("window.pageXOffset")
        win_width: float = page.evaluate("window.screen.width")
        win_height: float = page.evaluate("window.screen.height")
        win_right_bound: float = win_left_bound + win_width
        win_lower_bound: float = win_upper_bound + win_height
        # 		percentage_progress_start = (win_upper_bound / document_scroll_height) * 100
        # 		percentage_progress_end = (
        # 			(win_height + win_upper_bound) / document_scroll_height
        # 		) * 100
        percentage_progress_start = 1
        percentage_progress_end = 2
        page_state_as_text.append(
percentage_progress_end = 2
        page_state_as_text.append(
            {
                "x": 0,
                "y": 0,
                "text": "[scrollbar {:0.2f}-{:0.2f}%]".format(
                    round(percentage_progress_start, 2), round(percentage_progress_end)
                ),
            }
        )
        tree = self.client.send(
            "DOMSnapshot.captureSnapshot",
            {"computedStyles": [], "includeDOMRects": True, "includePaintOrder": True},
        )
        strings: Dict[int, str] = tree["strings"]
        document: Dict[str, Any] = tree["documents"][0]
        nodes: Dict[str, Any] = document["nodes"]
        backend_node_id: Dict[int, int] = nodes["backendNodeId"]
        attributes: Dict[int, Dict[int, Any]] = nodes["attributes"]
        node_value: Dict[int, int] = nodes["nodeValue"]
        parent: Dict[int, int] = nodes["parentIndex"]
        node_names: Dict[int, int] = nodes["nodeName"]
        is_clickable: Set[int] = set(nodes["isClickable"]["index"])
        input_value: Dict[str, Any] = nodes["inputValue"]
        input_value_index: List[int] = input_value["index"]
        input_value_values: List[int] = input_value["value"]
        layout: Dict[str, Any] = document["layout"]
        layout_node_index: List[int] = layout["nodeIndex"]
        bounds: Dict[int, List[float]] = layout["bounds"]
        cursor: int = 0
        child_nodes: Dict[str, List[Dict[str, Any]]] = {}
        elements_in_view_port: List[ElementInViewPort] = []
elements_in_view_port: List[ElementInViewPort] = []
        anchor_ancestry: Dict[str, Tuple[bool, Optional[int]]] = {"-1": (False, None)}
        button_ancestry: Dict[str, Tuple[bool, Optional[int]]] = {"-1": (False, None)}
        def convert_name(
            node_name: Optional[str], has_click_handler: Optional[bool]
        ) -> str:
            if node_name == "a":
                return "link"
            if node_name == "input":
                return "input"
            if node_name == "img":
                return "img"
            if (
                node_name == "button" or has_click_handler
            ):  # found pages that needed this quirk
                return "button"
            else:
                return "text"
        def find_attributes(
            attributes: Dict[int, Any], keys: List[str]
        ) -> Dict[str, str]:
            values = {}
            for [key_index, value_index] in zip(*(iter(attributes),) * 2):
                if value_index < 0:
                    continue
                key = strings[key_index]
                value = strings[value_index]
                if key in keys:
                    values[key] = value
                    keys.remove(key)
                    if not keys:
                        return values
            return values
        def add_to_hash_tree(
            hash_tree: Dict[str, Tuple[bool, Optional[int]]],
            tag: str,
            node_id: int,
            node_name: Optional[str],
            parent_id: int,
        ) -> Tuple[bool, Optional[int]]:
            parent_id_str = str(parent_id)
            if not parent_id_str in hash_tree:
if not parent_id_str in hash_tree:
                parent_name = strings[node_names[parent_id]].lower()
                grand_parent_id = parent[parent_id]
                add_to_hash_tree(
                    hash_tree, tag, parent_id, parent_name, grand_parent_id
                )
            is_parent_desc_anchor, anchor_id = hash_tree[parent_id_str]
            # even if the anchor is nested in another anchor, we set the "root" for all descendants to be ::Self
            if node_name == tag:
                value: Tuple[bool, Optional[int]] = (True, node_id)
            elif (
                is_parent_desc_anchor
            ):  # reuse the parent's anchor_id (which could be much higher in the tree)
                value = (True, anchor_id)
            else:
                value = (
                    False,
                    None,
                )  # not a descendant of an anchor, most likely it will become text, an interactive element or discarded
            hash_tree[str(node_id)] = value
            return value
        for index, node_name_index in enumerate(node_names):
            node_parent = parent[index]
            node_name: Optional[str] = strings[node_name_index].lower()
            is_ancestor_of_anchor, anchor_id = add_to_hash_tree(
                anchor_ancestry, "a", index, node_name, node_parent
            )
            is_ancestor_of_button, button_id = add_to_hash_tree(
                button_ancestry, "button", index, node_name, node_parent
            )
            try:
                cursor = layout_node_index.index(
                    index
                )  # todo replace this with proper cursoring, ignoring the fact this is O(n^2) for the moment
            except:
                continue
            if node_name in black_listed_elements:
                continue
continue
            if node_name in black_listed_elements:
                continue
            [x, y, width, height] = bounds[cursor]
            x /= device_pixel_ratio
            y /= device_pixel_ratio
            width /= device_pixel_ratio
            height /= device_pixel_ratio
            elem_left_bound = x
            elem_top_bound = y
            elem_right_bound = x + width
            elem_lower_bound = y + height
            partially_is_in_viewport = (
                elem_left_bound < win_right_bound
                and elem_right_bound >= win_left_bound
                and elem_top_bound < win_lower_bound
                and elem_lower_bound >= win_upper_bound
            )
            if not partially_is_in_viewport:
                continue
            meta_data: List[str] = []
            # inefficient to grab the same set of keys for kinds of objects, but it's fine for now
            element_attributes = find_attributes(
                attributes[index], ["type", "placeholder", "aria-label", "title", "alt"]
            )
            ancestor_exception = is_ancestor_of_anchor or is_ancestor_of_button
            ancestor_node_key = (
                None
                if not ancestor_exception
                else str(anchor_id)
                if is_ancestor_of_anchor
                else str(button_id)
            )
            ancestor_node = (
                None
                if not ancestor_exception
                else child_nodes.setdefault(str(ancestor_node_key), [])
            )
            if node_name == "#text" and ancestor_exception and ancestor_node:
                text = strings[node_value[index]]
                if text == "|" or text == "•":
                    continue
                ancestor_node.append({"type": "type", "value": text})
            else:
                if (
                    node_name == "input" and element_attributes.get("type") == "submit"
node_name == "input" and element_attributes.get("type") == "submit"
                ) or node_name == "button":
                    node_name = "button"
                    element_attributes.pop(
                        "type", None
                    )  # prevent [button ... (button)..]
                for key in element_attributes:
                    if ancestor_exception and ancestor_node:
                        ancestor_node.append(
                            {
                                "type": "attribute",
                                "key": key,
                                "value": element_attributes[key],
                            }
                        )
                    else:
                        meta_data.append(element_attributes[key])
            element_node_value = None
            if node_value[index] >= 0:
                element_node_value = strings[node_value[index]]
                if (
                    element_node_value == "|"
                ):  # commonly used as a separator, does not add much context - lets save ourselves some token space
                    continue
            elif (
                node_name == "input"
                and index in input_value_index
                and element_node_value is None
            ):
                node_input_text_index = input_value_index.index(index)
                text_index = input_value_values[node_input_text_index]
                if node_input_text_index >= 0 and text_index >= 0:
                    element_node_value = strings[text_index]
            # remove redundant elements
            if ancestor_exception and (node_name != "a" and node_name != "button"):
                continue
            elements_in_view_port.append(
                {
                    "node_index": str(index),
                    "backend_node_id": backend_node_id[index],
                    "node_name": node_name,
                    "node_value": element_node_value,
                    "node_meta": meta_data,
                    "is_clickable": index in is_clickable,
                    "origin_x": int(x),
"origin_x": int(x),
                    "origin_y": int(y),
                    "center_x": int(x + (width / 2)),
                    "center_y": int(y + (height / 2)),
                }
            )
        # lets filter further to remove anything that does not hold any text nor has click handlers + merge text from leaf#text nodes with the parent
        elements_of_interest = []
        id_counter = 0
        for element in elements_in_view_port:
            node_index = element.get("node_index")
            node_name = element.get("node_name")
            element_node_value = element.get("node_value")
            node_is_clickable = element.get("is_clickable")
            node_meta_data: Optional[List[str]] = element.get("node_meta")
            inner_text = f"{element_node_value} " if element_node_value else ""
            meta = ""
            if node_index in child_nodes:
                for child in child_nodes[node_index]:
                    entry_type = child.get("type")
                    entry_value = child.get("value")
                    if entry_type == "attribute" and node_meta_data:
                        entry_key = child.get("key")
                        node_meta_data.append(f'{entry_key}="{entry_value}"')
                    else:
                        inner_text += f"{entry_value} "
            if node_meta_data:
                meta_string = " ".join(node_meta_data)
                meta = f" {meta_string}"
            if inner_text != "":
                inner_text = f"{inner_text.strip()}"
            converted_node_name = convert_name(node_name, node_is_clickable)
            # not very elegant, more like a placeholder
            if (
                (converted_node_name != "button" or meta == "")
                and converted_node_name != "link"