Add BERTopic.

This commit is contained in:
戒酒的李白
2025-08-12 19:01:20 +08:00
parent e2323d579c
commit c5c530775e
256 changed files with 28666 additions and 0 deletions
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import numpy as np
import pandas as pd
import logging
from collections.abc import Iterable
from scipy.sparse import csr_matrix
from scipy.spatial.distance import squareform
from typing import Optional, Union, Tuple
class MyLogger:
def __init__(self):
self.logger = logging.getLogger("BERTopic")
def configure(self, level):
self.set_level(level)
self._add_handler()
self.logger.propagate = False
def info(self, message):
self.logger.info(f"{message}")
def warning(self, message):
self.logger.warning(f"WARNING: {message}")
def set_level(self, level):
levels = ["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"]
if level in levels:
self.logger.setLevel(level)
def _add_handler(self):
sh = logging.StreamHandler()
sh.setFormatter(logging.Formatter("%(asctime)s - %(name)s - %(message)s"))
self.logger.addHandler(sh)
# Remove duplicate handlers
if len(self.logger.handlers) > 1:
self.logger.handlers = [self.logger.handlers[0]]
def check_documents_type(documents):
"""Check whether the input documents are indeed a list of strings."""
if isinstance(documents, pd.DataFrame):
raise TypeError("Make sure to supply a list of strings, not a dataframe.")
elif isinstance(documents, Iterable) and not isinstance(documents, str):
if not any([isinstance(doc, str) for doc in documents]):
raise TypeError("Make sure that the iterable only contains strings.")
else:
raise TypeError("Make sure that the documents variable is an iterable containing strings only.")
def check_embeddings_shape(embeddings, docs):
"""Check if the embeddings have the correct shape."""
if embeddings is not None:
if not any([isinstance(embeddings, np.ndarray), isinstance(embeddings, csr_matrix)]):
raise ValueError("Make sure to input embeddings as a numpy array or scipy.sparse.csr.csr_matrix. ")
else:
if embeddings.shape[0] != len(docs):
raise ValueError(
"Make sure that the embeddings are a numpy array with shape: "
"(len(docs), vector_dim) where vector_dim is the dimensionality "
"of the vector embeddings. "
)
def check_is_fitted(topic_model):
"""Checks if the model was fitted by verifying the presence of self.matches.
Arguments:
topic_model: BERTopic instance for which the check is performed.
Returns:
None
Raises:
ValueError: If the matches were not found.
"""
msg = "This %(name)s instance is not fitted yet. Call 'fit' with appropriate arguments before using this estimator."
if topic_model.topics_ is None:
raise ValueError(msg % {"name": type(topic_model).__name__})
class NotInstalled:
"""This object is used to notify the user that additional dependencies need to be
installed in order to use the string matching model.
"""
def __init__(self, tool, dep, custom_msg=None):
self.tool = tool
self.dep = dep
msg = f"In order to use {self.tool} you will need to install via;\n\n"
if custom_msg is not None:
msg += custom_msg
else:
msg += f"pip install bertopic[{self.dep}]\n\n"
self.msg = msg
def __getattr__(self, *args, **kwargs):
raise ModuleNotFoundError(self.msg)
def __call__(self, *args, **kwargs):
raise ModuleNotFoundError(self.msg)
def validate_distance_matrix(X, n_samples):
"""Validate the distance matrix and convert it to a condensed distance matrix
if necessary.
A valid distance matrix is either a square matrix of shape (n_samples, n_samples)
with zeros on the diagonal and non-negative values or condensed distance matrix
of shape (n_samples * (n_samples - 1) / 2,) containing the upper triangular of the
distance matrix.
Arguments:
X: Distance matrix to validate.
n_samples: Number of samples in the dataset.
Returns:
X: Validated distance matrix.
Raises:
ValueError: If the distance matrix is not valid.
"""
# Make sure it is the 1-D condensed distance matrix with zeros on the diagonal
s = X.shape
if len(s) == 1:
# check it has correct size
n = s[0]
if n != (n_samples * (n_samples - 1) / 2):
raise ValueError("The condensed distance matrix must have shape (n*(n-1)/2,).")
elif len(s) == 2:
# check it has correct size
if (s[0] != n_samples) or (s[1] != n_samples):
raise ValueError("The distance matrix must be of shape (n, n) where n is the number of samples.")
# force zero diagonal and convert to condensed
np.fill_diagonal(X, 0)
X = squareform(X)
else:
raise ValueError(
"The distance matrix must be either a 1-D condensed "
"distance matrix of shape (n*(n-1)/2,) or a "
"2-D square distance matrix of shape (n, n)."
"where n is the number of documents."
"Got a distance matrix of shape %s" % str(s)
)
# Make sure its entries are non-negative
if np.any(X < 0):
raise ValueError("Distance matrix cannot contain negative values.")
return X
def get_unique_distances(dists: np.array, noise_max=1e-7) -> np.array:
"""Check if the consecutive elements in the distance array are the same. If so, a small noise
is added to one of the elements to make sure that the array does not contain duplicates.
Arguments:
dists: distance array sorted in the increasing order.
noise_max: the maximal magnitude of noise to be added.
Returns:
Unique distances sorted in the preserved increasing order.
"""
dists_cp = dists.copy()
for i in range(dists.shape[0] - 1):
if dists[i] == dists[i + 1]:
# returns the next unique distance or the current distance with the added noise
next_unique_dist = next((d for d in dists[i + 1 :] if d != dists[i]), dists[i] + noise_max)
# the noise can never be large then the difference between the next unique distance and the current one
curr_max_noise = min(noise_max, next_unique_dist - dists_cp[i])
dists_cp[i + 1] = np.random.uniform(low=dists_cp[i] + curr_max_noise / 2, high=dists_cp[i] + curr_max_noise)
return dists_cp
def select_topic_representation(
ctfidf_embeddings: Optional[Union[np.ndarray, csr_matrix]] = None,
embeddings: Optional[Union[np.ndarray, csr_matrix]] = None,
use_ctfidf: bool = True,
output_ndarray: bool = False,
) -> Tuple[np.ndarray, bool]:
"""Select the topic representation.
Arguments:
ctfidf_embeddings: The c-TF-IDF embedding matrix
embeddings: The topic embedding matrix
use_ctfidf: Whether to use the c-TF-IDF representation. If False, topics embedding representation is used, if it
exists. Default is True.
output_ndarray: Whether to convert the selected representation into ndarray
Raises
ValueError:
- If no topic representation was found
- If c-TF-IDF embeddings are not a numpy array or a scipy.sparse.csr_matrix
Returns:
The selected topic representation and a boolean indicating whether it is c-TF-IDF.
"""
def to_ndarray(array: Union[np.ndarray, csr_matrix]) -> np.ndarray:
if isinstance(array, csr_matrix):
return array.toarray()
return array
logger = MyLogger()
if use_ctfidf:
if ctfidf_embeddings is None:
logger.warning(
"No c-TF-IDF matrix was found despite it is supposed to be used (`use_ctfidf` is True). "
"Defaulting to semantic embeddings."
)
repr_, ctfidf_used = embeddings, False
else:
repr_, ctfidf_used = ctfidf_embeddings, True
else:
if embeddings is None:
logger.warning(
"No topic embeddings were found despite they are supposed to be used (`use_ctfidf` is False). "
"Defaulting to c-TF-IDF representation."
)
repr_, ctfidf_used = ctfidf_embeddings, True
else:
repr_, ctfidf_used = embeddings, False
return to_ndarray(repr_) if output_ndarray else repr_, ctfidf_used