viruPVS/langchain-docs huggingface dataset:
attrfind_tolerant = re.compile(
    r'((?<=[\'"\s/])[^\s/>][^\s/=>]*)(\s*=+\s*'
    r'(\'[^\']*\'|"[^"]*"|(?![\'"])[^>\s]*))?(?:\s|/(?!>))*')
locatestarttagend_tolerant = re.compile(r"""
  <[a-zA-Z][^\t\n\r\f />\x00]*       # tag name
  (?:[\s/]*                          # optional whitespace before attribute name
    (?:(?<=['"\s/])[^\s/>][^\s/=>]*  # attribute name
      (?:\s*=+\s*                    # value indicator
        (?:'[^']*'                   # LITA-enclosed value
          |"[^"]*"                   # LIT-enclosed value
          |(?!['"])[^>\s]*           # bare value
         )
        \s*                          # possibly followed by a space
       )?(?:\s|/(?!>))*
     )*
   )?
  \s*                                # trailing whitespace
""", re.VERBOSE)
endendtag = re.compile('>')
# the HTML 5 spec, section 8.1.2.2, doesn't allow spaces between
# </ and the tag name, so maybe this should be fixed
endtagfind = re.compile(r'</\s*([a-zA-Z][-.a-zA-Z0-9:_]*)\s*>')
class HTMLParser(_markupbase.ParserBase):
    """Find tags and other markup and call handler functions.
    Usage:
        p = HTMLParser()
        p.feed(data)
        ...
        p.close()
    Start tags are handled by calling self.handle_starttag() or
p.close()
    Start tags are handled by calling self.handle_starttag() or
    self.handle_startendtag(); end tags by self.handle_endtag().  The
    data between tags is passed from the parser to the derived class
    by calling self.handle_data() with the data as argument (the data
    may be split up in arbitrary chunks).  If convert_charrefs is
    True the character references are converted automatically to the
    corresponding Unicode character (and self.handle_data() is no
    longer split in chunks), otherwise they are passed by calling
    self.handle_entityref() or self.handle_charref() with the string
    containing respectively the named or numeric reference as the
    argument.
    """
    CDATA_CONTENT_ELEMENTS = ("script", "style")
    def __init__(self, *, convert_charrefs=True):
        """Initialize and reset this instance.
        If convert_charrefs is True (the default), all character references
        are automatically converted to the corresponding Unicode characters.
        """
        self.convert_charrefs = convert_charrefs
        self.reset()
    def reset(self):
        """Reset this instance.  Loses all unprocessed data."""
        self.rawdata = ''
        self.lasttag = '???'
        self.interesting = interesting_normal
        self.cdata_elem = None
        _markupbase.ParserBase.reset(self)
    def feed(self, data):
        r"""Feed data to the parser.
        Call this as often as you want, with as little or as much text
        as you want (may include '\n').
        """
        self.rawdata = self.rawdata + data
        self.goahead(0)
    def close(self):
        """Handle any buffered data."""
        self.goahead(1)
    __starttag_text = None
self.goahead(1)
    __starttag_text = None
    def get_starttag_text(self):
        """Return full source of start tag: '<...>'."""
        return self.__starttag_text
    def set_cdata_mode(self, elem):
        self.cdata_elem = elem.lower()
        self.interesting = re.compile(r'</\s*%s\s*>' % self.cdata_elem, re.I)
    def clear_cdata_mode(self):
        self.interesting = interesting_normal
        self.cdata_elem = None
    # Internal -- handle data as far as reasonable.  May leave state
    # and data to be processed by a subsequent call.  If 'end' is
    # true, force handling all data as if followed by EOF marker.
    def goahead(self, end):
        rawdata = self.rawdata
        i = 0
        n = len(rawdata)
        while i < n:
            if self.convert_charrefs and not self.cdata_elem:
                j = rawdata.find('<', i)
                if j < 0:
                    # if we can't find the next <, either we are at the end
                    # or there's more text incoming.  If the latter is True,
                    # we can't pass the text to handle_data in case we have
                    # a charref cut in half at end.  Try to determine if
                    # this is the case before proceeding by looking for an
                    # & near the end and see if it's followed by a space or ;.
                    amppos = rawdata.rfind('&', max(i, n-34))
                    if (amppos >= 0 and
                        not re.compile(r'[\s;]').search(rawdata, amppos)):
not re.compile(r'[\s;]').search(rawdata, amppos)):
                        break  # wait till we get all the text
                    j = n
            else:
                match = self.interesting.search(rawdata, i)  # < or &
                if match:
                    j = match.start()
                else:
                    if self.cdata_elem:
                        break
                    j = n
            if i < j:
                if self.convert_charrefs and not self.cdata_elem:
                    self.handle_data(unescape(rawdata[i:j]))
                else:
                    self.handle_data(rawdata[i:j])
            i = self.updatepos(i, j)
            if i == n: break
            startswith = rawdata.startswith
            if startswith('<', i):
                if starttagopen.match(rawdata, i): # < + letter
                    k = self.parse_starttag(i)
                elif startswith("</", i):
                    k = self.parse_endtag(i)
                elif startswith("<!--", i):
                    k = self.parse_comment(i)
                elif startswith("<?", i):
                    k = self.parse_pi(i)
                elif startswith("<!", i):
                    k = self.parse_html_declaration(i)
                elif (i + 1) < n:
                    self.handle_data("<")
                    k = i + 1
                else:
                    break
                if k < 0:
                    if not end:
                        break
                    k = rawdata.find('>', i + 1)
                    if k < 0:
                        k = rawdata.find('<', i + 1)
                        if k < 0:
                            k = i + 1
                    else:
                        k += 1
k = i + 1
                    else:
                        k += 1
                    if self.convert_charrefs and not self.cdata_elem:
                        self.handle_data(unescape(rawdata[i:k]))
                    else:
                        self.handle_data(rawdata[i:k])
                i = self.updatepos(i, k)
            elif startswith("&#", i):
                match = charref.match(rawdata, i)
                if match:
                    name = match.group()[2:-1]
                    self.handle_charref(name)
                    k = match.end()
                    if not startswith(';', k-1):
                        k = k - 1
                    i = self.updatepos(i, k)
                    continue
                else:
                    if ";" in rawdata[i:]:  # bail by consuming &#
                        self.handle_data(rawdata[i:i+2])
                        i = self.updatepos(i, i+2)
                    break
            elif startswith('&', i):
                match = entityref.match(rawdata, i)
                if match:
                    name = match.group(1)
                    self.handle_entityref(name)
                    k = match.end()
                    if not startswith(';', k-1):
                        k = k - 1
                    i = self.updatepos(i, k)
                    continue
                match = incomplete.match(rawdata, i)
                if match:
                    # match.group() will contain at least 2 chars
                    if end and match.group() == rawdata[i:]:
                        k = match.end()
                        if k <= i:
                            k = n
                        i = self.updatepos(i, i + 1)
                    # incomplete
                    break
                elif (i + 1) < n:
                    # not the end of the buffer, and can't be confused
# not the end of the buffer, and can't be confused
                    # with some other construct
                    self.handle_data("&")
                    i = self.updatepos(i, i + 1)
                else:
                    break
            else:
                assert 0, "interesting.search() lied"
        # end while
        if end and i < n and not self.cdata_elem:
            if self.convert_charrefs and not self.cdata_elem:
                self.handle_data(unescape(rawdata[i:n]))
            else:
                self.handle_data(rawdata[i:n])
            i = self.updatepos(i, n)
        self.rawdata = rawdata[i:]
    # Internal -- parse html declarations, return length or -1 if not terminated
    # See w3.org/TR/html5/tokenization.html#markup-declaration-open-state
    # See also parse_declaration in _markupbase
    def parse_html_declaration(self, i):
        rawdata = self.rawdata
        assert rawdata[i:i+2] == '<!', ('unexpected call to '
                                        'parse_html_declaration()')
        if rawdata[i:i+4] == '<!--':
            # this case is actually already handled in goahead()
            return self.parse_comment(i)
        elif rawdata[i:i+3] == '<![':
            return self.parse_marked_section(i)
        elif rawdata[i:i+9].lower() == '<!doctype':
            # find the closing >
            gtpos = rawdata.find('>', i+9)
            if gtpos == -1:
                return -1
            self.handle_decl(rawdata[i+2:gtpos])
            return gtpos+1
        else:
            return self.parse_bogus_comment(i)
else:
            return self.parse_bogus_comment(i)
    # Internal -- parse bogus comment, return length or -1 if not terminated
    # see http://www.w3.org/TR/html5/tokenization.html#bogus-comment-state
    def parse_bogus_comment(self, i, report=1):
        rawdata = self.rawdata
        assert rawdata[i:i+2] in ('<!', '</'), ('unexpected call to '
                                                'parse_comment()')
        pos = rawdata.find('>', i+2)
        if pos == -1:
            return -1
        if report:
            self.handle_comment(rawdata[i+2:pos])
        return pos + 1
    # Internal -- parse processing instr, return end or -1 if not terminated
    def parse_pi(self, i):
        rawdata = self.rawdata
        assert rawdata[i:i+2] == '<?', 'unexpected call to parse_pi()'
        match = piclose.search(rawdata, i+2) # >
        if not match:
            return -1
        j = match.start()
        self.handle_pi(rawdata[i+2: j])
        j = match.end()
        return j
    # Internal -- handle starttag, return end or -1 if not terminated
    def parse_starttag(self, i):
        self.__starttag_text = None
        endpos = self.check_for_whole_start_tag(i)
        if endpos < 0:
            return endpos
        rawdata = self.rawdata
        self.__starttag_text = rawdata[i:endpos]
        # Now parse the data between i+1 and j into a tag and attrs
        attrs = []
        match = tagfind_tolerant.match(rawdata, i+1)
match = tagfind_tolerant.match(rawdata, i+1)
        assert match, 'unexpected call to parse_starttag()'
        k = match.end()
        self.lasttag = tag = match.group(1).lower()
        while k < endpos:
            m = attrfind_tolerant.match(rawdata, k)
            if not m:
                break
            attrname, rest, attrvalue = m.group(1, 2, 3)
            if not rest:
                attrvalue = None
            elif attrvalue[:1] == '\'' == attrvalue[-1:] or \
                 attrvalue[:1] == '"' == attrvalue[-1:]:
                attrvalue = attrvalue[1:-1]
            if attrvalue:
                attrvalue = unescape(attrvalue)
            attrs.append((attrname.lower(), attrvalue))
            k = m.end()
        end = rawdata[k:endpos].strip()
        if end not in (">", "/>"):
            self.handle_data(rawdata[i:endpos])
            return endpos
        if end.endswith('/>'):
            # XHTML-style empty tag: <span attr="value" />
            self.handle_startendtag(tag, attrs)
        else:
            self.handle_starttag(tag, attrs)
            if tag in self.CDATA_CONTENT_ELEMENTS:
                self.set_cdata_mode(tag)
        return endpos
    # Internal -- check to see if we have a complete starttag; return end
    # or -1 if incomplete.
    def check_for_whole_start_tag(self, i):
        rawdata = self.rawdata
        m = locatestarttagend_tolerant.match(rawdata, i)
        if m:
            j = m.end()
            next = rawdata[j:j+1]
j = m.end()
            next = rawdata[j:j+1]
            if next == ">":
                return j + 1
            if next == "/":
                if rawdata.startswith("/>", j):
                    return j + 2
                if rawdata.startswith("/", j):
                    # buffer boundary
                    return -1
                # else bogus input
                if j > i:
                    return j
                else:
                    return i + 1
            if next == "":
                # end of input
                return -1
            if next in ("abcdefghijklmnopqrstuvwxyz=/"
                        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"):
                # end of input in or before attribute value, or we have the
                # '/' from a '/>' ending
                return -1
            if j > i:
                return j
            else:
                return i + 1
        raise AssertionError("we should not get here!")
    # Internal -- parse endtag, return end or -1 if incomplete
    def parse_endtag(self, i):
        rawdata = self.rawdata
        assert rawdata[i:i+2] == "</", "unexpected call to parse_endtag"
        match = endendtag.search(rawdata, i+1) # >
        if not match:
            return -1
        gtpos = match.end()
        match = endtagfind.match(rawdata, i) # </ + tag + >
        if not match:
            if self.cdata_elem is not None:
                self.handle_data(rawdata[i:gtpos])
                return gtpos
            # find the name: w3.org/TR/html5/tokenization.html#tag-name-state
            namematch = tagfind_tolerant.match(rawdata, i+2)
            if not namematch:
if not namematch:
                # w3.org/TR/html5/tokenization.html#end-tag-open-state
                if rawdata[i:i+3] == '</>':
                    return i+3
                else:
                    return self.parse_bogus_comment(i)
            tagname = namematch.group(1).lower()
            # consume and ignore other stuff between the name and the >
            # Note: this is not 100% correct, since we might have things like
            # </tag attr=">">, but looking for > after the name should cover
            # most of the cases and is much simpler
            gtpos = rawdata.find('>', namematch.end())
            self.handle_endtag(tagname)
            return gtpos+1
        elem = match.group(1).lower() # script or style
        if self.cdata_elem is not None:
            if elem != self.cdata_elem:
                self.handle_data(rawdata[i:gtpos])
                return gtpos
        self.handle_endtag(elem)
        self.clear_cdata_mode()
        return gtpos
    # Overridable -- finish processing of start+end tag: <tag.../>
    def handle_startendtag(self, tag, attrs):
        self.handle_starttag(tag, attrs)
        self.handle_endtag(tag)
    # Overridable -- handle start tag
    def handle_starttag(self, tag, attrs):
        pass
    # Overridable -- handle end tag
    def handle_endtag(self, tag):
        pass
    # Overridable -- handle character reference
    def handle_charref(self, name):
        pass
    # Overridable -- handle entity reference
    def handle_entityref(self, name):
        pass
    # Overridable -- handle data
pass
    # Overridable -- handle data
    def handle_data(self, data):
        pass
    # Overridable -- handle comment
    def handle_comment(self, data):
        pass
    # Overridable -- handle declaration
    def handle_decl(self, decl):
        pass
    # Overridable -- handle processing instruction
    def handle_pi(self, data):
        pass
    def unknown_decl(self, data):
        pass
Source code for langchain_core.stores
from abc import ABC, abstractmethod
from typing import Generic, Iterator, List, Optional, Sequence, Tuple, TypeVar, Union
K = TypeVar("K")
V = TypeVar("V")
[docs]class BaseStore(Generic[K, V], ABC):
    """Abstract interface for a key-value store."""
[docs]    @abstractmethod
    def mget(self, keys: Sequence[K]) -> List[Optional[V]]:
        """Get the values associated with the given keys.
        Args:
            keys (Sequence[K]): A sequence of keys.
        Returns:
            A sequence of optional values associated with the keys.
            If a key is not found, the corresponding value will be None.
        """
[docs]    @abstractmethod
    def mset(self, key_value_pairs: Sequence[Tuple[K, V]]) -> None:
        """Set the values for the given keys.
        Args:
            key_value_pairs (Sequence[Tuple[K, V]]): A sequence of key-value pairs.
        """
[docs]    @abstractmethod
    def mdelete(self, keys: Sequence[K]) -> None:
        """Delete the given keys and their associated values.
        Args:
            keys (Sequence[K]): A sequence of keys to delete.
        """
[docs]    @abstractmethod
    def yield_keys(
        self, *, prefix: Optional[str] = None
    ) -> Union[Iterator[K], Iterator[str]]:
        """Get an iterator over keys that match the given prefix.
        Args:
            prefix (str): The prefix to match.
        Returns:
            Iterator[K | str]: An iterator over keys that match the given prefix.
            This method is allowed to return an iterator over either K or str
Source code for langchain_core.vectorstores
from __future__ import annotations
import asyncio
import logging
import math
import warnings
from abc import ABC, abstractmethod
from functools import partial
from typing import (
    TYPE_CHECKING,
    Any,
    Callable,
    ClassVar,
    Collection,
    Dict,
    Iterable,
    List,
    Optional,
    Tuple,
    Type,
    TypeVar,
)
from langchain_core.embeddings import Embeddings
from langchain_core.pydantic_v1 import Field, root_validator
from langchain_core.retrievers import BaseRetriever
if TYPE_CHECKING:
    from langchain_core.callbacks.manager import (
        AsyncCallbackManagerForRetrieverRun,
        CallbackManagerForRetrieverRun,
    )
    from langchain_core.documents import Document
logger = logging.getLogger(__name__)
VST = TypeVar("VST", bound="VectorStore")
[docs]class VectorStore(ABC):
    """Interface for vector store."""
[docs]    @abstractmethod
    def add_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        **kwargs: Any,
    ) -> List[str]:
        """Run more texts through the embeddings and add to the vectorstore.
        Args:
            texts: Iterable of strings to add to the vectorstore.
            metadatas: Optional list of metadatas associated with the texts.
            kwargs: vectorstore specific parameters
        Returns:
            List of ids from adding the texts into the vectorstore.
        """
    @property
    def embeddings(self) -> Optional[Embeddings]:
        """Access the query embedding object if available."""
        logger.debug(
"""Access the query embedding object if available."""
        logger.debug(
            f"{Embeddings.__name__} is not implemented for {self.__class__.__name__}"
        )
        return None
[docs]    def delete(self, ids: Optional[List[str]] = None, **kwargs: Any) -> Optional[bool]:
        """Delete by vector ID or other criteria.
        Args:
            ids: List of ids to delete.
            **kwargs: Other keyword arguments that subclasses might use.
        Returns:
            Optional[bool]: True if deletion is successful,
            False otherwise, None if not implemented.
        """
        raise NotImplementedError("delete method must be implemented by subclass.")
[docs]    async def adelete(
        self, ids: Optional[List[str]] = None, **kwargs: Any
    ) -> Optional[bool]:
        """Delete by vector ID or other criteria.
        Args:
            ids: List of ids to delete.
            **kwargs: Other keyword arguments that subclasses might use.
        Returns:
            Optional[bool]: True if deletion is successful,
            False otherwise, None if not implemented.
        """
        raise NotImplementedError("delete method must be implemented by subclass.")
[docs]    async def aadd_texts(
        self,
        texts: Iterable[str],
        metadatas: Optional[List[dict]] = None,
        **kwargs: Any,
    ) -> List[str]:
        """Run more texts through the embeddings and add to the vectorstore."""
        return await asyncio.get_running_loop().run_in_executor(
            None, partial(self.add_texts, **kwargs), texts, metadatas
        )
[docs]    def add_documents(self, documents: List[Document], **kwargs: Any) -> List[str]:
"""Run more documents through the embeddings and add to the vectorstore.
        Args:
            documents (List[Document]: Documents to add to the vectorstore.
        Returns:
            List[str]: List of IDs of the added texts.
        """
        # TODO: Handle the case where the user doesn't provide ids on the Collection
        texts = [doc.page_content for doc in documents]
        metadatas = [doc.metadata for doc in documents]
        return self.add_texts(texts, metadatas, **kwargs)
[docs]    async def aadd_documents(
        self, documents: List[Document], **kwargs: Any
    ) -> List[str]:
        """Run more documents through the embeddings and add to the vectorstore.
        Args:
            documents (List[Document]: Documents to add to the vectorstore.
        Returns:
            List[str]: List of IDs of the added texts.
        """
        texts = [doc.page_content for doc in documents]
        metadatas = [doc.metadata for doc in documents]
        return await self.aadd_texts(texts, metadatas, **kwargs)
[docs]    def search(self, query: str, search_type: str, **kwargs: Any) -> List[Document]:
        """Return docs most similar to query using specified search type."""
        if search_type == "similarity":
            return self.similarity_search(query, **kwargs)
        elif search_type == "mmr":
            return self.max_marginal_relevance_search(query, **kwargs)
        else:
            raise ValueError(
                f"search_type of {search_type} not allowed. Expected "
                "search_type to be 'similarity' or 'mmr'."
            )
[docs]    async def asearch(
)
[docs]    async def asearch(
        self, query: str, search_type: str, **kwargs: Any
    ) -> List[Document]:
        """Return docs most similar to query using specified search type."""
        if search_type == "similarity":
            return await self.asimilarity_search(query, **kwargs)
        elif search_type == "mmr":
            return await self.amax_marginal_relevance_search(query, **kwargs)
        else:
            raise ValueError(
                f"search_type of {search_type} not allowed. Expected "
                "search_type to be 'similarity' or 'mmr'."
            )
[docs]    @abstractmethod
    def similarity_search(
        self, query: str, k: int = 4, **kwargs: Any
    ) -> List[Document]:
        """Return docs most similar to query."""
    @staticmethod
    def _euclidean_relevance_score_fn(distance: float) -> float:
        """Return a similarity score on a scale [0, 1]."""
        # The 'correct' relevance function
        # may differ depending on a few things, including:
        # - the distance / similarity metric used by the VectorStore
        # - the scale of your embeddings (OpenAI's are unit normed. Many
        #  others are not!)
        # - embedding dimensionality
        # - etc.
        # This function converts the euclidean norm of normalized embeddings
        # (0 is most similar, sqrt(2) most dissimilar)
        # to a similarity function (0 to 1)
        return 1.0 - distance / math.sqrt(2)
    @staticmethod
    def _cosine_relevance_score_fn(distance: float) -> float: