llm-utility-pack 3.41

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This is a collection of utility functions and decorators that can be used in various projects.

1. Utility Decorators

This module provides a collection of useful decorators for caching, disk-based caching, and retrying function executions.

How to Import:

from utility_pack.decorators import <DecoratorName>

---

timed_lru_cache

Caches function results in memory with a time-based expiration and LRU eviction policy.

from utility_pack.decorators import timed_lru_cache
import time

@timed_lru_cache(max_size=2, minutes=5)  # Max 2 items, expire after 5 minutes
def expensive_operation(arg):
    print("Calculating...")
    time.sleep(1)  # Simulate a slow operation
    return arg * 2

print(expensive_operation(5))  # Calculates and prints 10
print(expensive_operation(5))  # Returns cached result (10) immediately

disk_lru_cache

Caches function results to disk using a LRU eviction policy. This is useful for persisting results across multiple program invocations or in situations where in-memory caching is insufficient. Note that the function's return value MUST be pickleable.
The disk caching implementation relies on cloudpickle, allowing for a wider range of Python objects (including lambdas, functions, and classes) to be serialized and cached, which the standard pickle module does not support.

from utility_pack.decorators import disk_lru_cache
import os

@disk_lru_cache(max_size=2, cache_file="my_cache.pkl")
def another_expensive_operation(arg):
    print("Calculating from Disk...")
    return arg * 3

print(another_expensive_operation(4))  # Calculates and prints 12, saves to disk
print(another_expensive_operation(4))  # Retrieves from disk cache (12)
os.remove("my_cache.pkl") #cleanup

custom_lru_cache

Same as python's native lru_cache, but with a custom implementation that allows to cache more complex data structures, via an interna hashing mechanism.

from utility_pack.decorators import custom_lru_cache
import os

@custom_lru_cache(max_size=100)
def another_expensive_operation(arg):
    print("Calculating from Disk...")
    return arg * 3

print(another_expensive_operation(4))  # Calculates and prints 12, saves to cache
print(another_expensive_operation(4))  # Retrieves from cache

---

retry

Retries a function execution a specified number of times if it raises an exception.

from utility_pack.decorators import retry

@retry(retry_count=3, delay=0.5) # Retry thrice, delayed 0.5 seconds between attempts
def flaky_function():
    import random
    if random.random() < 0.5:
        raise ValueError("Something went wrong!")
    return "Success!"

print(flaky_function())

2. Embeddings

utility_pack.embeddings Module

This module provides functionalities for extracting text embeddings using different methods. It includes options for both textual (character-based n-grams) and semantic (ONNX transformer model based) embeddings.

To import the functionalities, use the following pattern: from utility_pack.embeddings import <function_or_class_name>

extract_embeddings Function

This function is the main entry point for extracting embeddings. It takes a list of texts and an optional embedding_type argument to specify the desired embedding method.

from utility_pack.embeddings import extract_embeddings, EmbeddingType

texts = ["This is a sample text.", "Another sample text."]

# Example: Extracting textual embeddings
textual_embeddings = extract_embeddings(texts, embedding_type=EmbeddingType.TEXTUAL)
print(f"Textual embeddings shape: {len(textual_embeddings), len(textual_embeddings[0])}")

# Example: Extracting semantic embeddings
semantic_embeddings = extract_embeddings(texts, embedding_type=EmbeddingType.SEMANTIC)
print(f"Semantic embeddings shape: {len(semantic_embeddings), len(semantic_embeddings[0])}")

Parameters:

• texts: A list of strings to be embedded.
• embedding_type: An EmbeddingType enum value specifying the desired embedding method (default: EmbeddingType.TEXTUAL).

Returns:

A list of embeddings represented as lists of floats. The format depends on the embedding_type.

Textual Embeddings using HashingVectorizer

Implements character-based n-gram embeddings using scikit-learn's HashingVectorizer.

from utility_pack.embeddings import extract_embeddings, EmbeddingType

texts = ["Simple and short text.", "Another short sample."]
textual_embeddings = extract_embeddings(texts, embedding_type=EmbeddingType.TEXTUAL)
print(f"Textual embeddings for short texts: {len(textual_embeddings), len(textual_embeddings[0])}")

Semantic Embeddings using ONNX Transformer Model

Leverages a pre-trained ONNX transformer model to generate semantic embeddings. It uses a provided tokenizer to tokenize the input text and utilizes the ONNX runtime for inference. It first compresses the text (if longer than 500 tokens) with compress_text and then feeds to the transformer model.

from utility_pack.embeddings import extract_embeddings, EmbeddingType

texts = ["A longer sentence for semantic analysis.", "Another example of a moderately long sentence."]
semantic_embeddings = extract_embeddings(texts, embedding_type=EmbeddingType.SEMANTIC)
print(f"Semantic embeddings for moderately long sentences {len(semantic_embeddings), len(semantic_embeddings[0])}")  #  len(semantic_embeddings) equal total texts.

3. Interact with LLMs

utility_pack.llm

This module provides functions to interact with LLMs from OpenRouter, Ollama, vLLM, and OpenAI. It supports chat and prompt formats, both streaming and non-streaming.

# Functions that iteract with LLMs, based on environment variables

# PROVIDER: which provider to use, must be one of ['openrouter', 'ollama', 'vllm', 'openai']
# OPENROUTER_KEY
# OLLAMA_HOST, defaults to http://127.0.0.1:11434
# VLLM_URL, defaults to http://127.0.0.1:8000
# OPENAI_API_KEY

from utility_pack.llm import llm_chat, llm_prompt, llm_chat_async, llm_prompt_async, llm_prompt_stream, llm_chat_stream

Classify Question (Generic or Directed)

Classifies a question as either "generic" or "directed" using a pre-trained ONNX model.

from utility_pack.llm import classify_question_generic_or_directed
question = "What is the meaning of life?"
classification = classify_question_generic_or_directed(question)
print(f"The question is classified as: {classification}")

Passage Re-ranking

Re-ranks a list of passages based on their relevance to a given question using a pre-trained ONNX model.

from utility_pack.llm import rerank
question = "What are the benefits of exercise?"
passages = [
    "Exercise improves cardiovascular health.",
    "Eating a balanced diet is important for overall well-being.",
    "Regular exercise can help reduce stress and improve mood."
]
ranked_passages = rerank(question, passages)
for passage, score in ranked_passages:
    print(f"Passage: {passage}, Score: {score}")

4. Logging

This module provides utility functions for logging exceptions with detailed information, including date/time in Brasilia time zone, filename, function name, line number, stack trace and parameters.

To import this module:

from utility_pack.logger import get_datetime_brasilia, log_exception

get_datetime_brasilia()

Returns the current date and time in the "America/Sao_Paulo" timezone (Brasilia) formatted as a string.

Example:

from utility_pack.logger import get_datetime_brasilia

current_time = get_datetime_brasilia()
print(current_time) # Output: e.g., 20/10/2023 - 15:30:45

log_exception()

Logs an exception along with detailed context information - Brasilia datetime, filename, function name, line number, full stack trace and function arguments up to 100 characters. The error message is logged using the Python logging module at the ERROR level. This is intended to be called inside an except block.

Example:

from utility_pack.logger import log_exception

def some_function(a, b):
    try:
        result = a / b
        return result
    except ZeroDivisionError:
        log_exception()

result = some_function(10, 0)
print(result) # Output (in console): None

# Will print out the exception in high detail automatically

5. ML

timeseries_forecast

Creates a time series forecast using the Prophet model.

Parameters:

• dates (list): List of dates. Should be compatible with Prophet's date format.
• values (list): List of corresponding numerical values.
• num_forecast_periods (int, optional): Number of periods to forecast into the future. Defaults to 30.

Returns:

• list: A list of forecasted values for the specified number of periods.

Example:

from utility_pack.ml import timeseries_forecast
dates = ['2023-01-01', '2023-01-02', '2023-01-03', '2023-01-04', '2023-01-05']
values = [10, 12, 15, 13, 17]
forecast = timeseries_forecast(dates, values, num_forecast_periods=7)
print(forecast)

---

find_high_correlation_features

Identifies and returns a list of highly correlated features in a DataFrame.

Parameters:

• df (pd.DataFrame): The input DataFrame.
• categorical_columns (list): List of categorical column names.
• ignore_columns (list): List of columns to ignore.
• threshold (float, optional): The correlation threshold. Columns with correlation above this value are returned. Defaults to 0.9.

Returns:

• list: A list of column names that are highly correlated with other columns.

Example:

import pandas as pd
from utility_pack.ml import find_high_correlation_features

data = {'col1': [1, 2, 3, 4, 5], 'col2': [2, 4, 6, 8, 10], 'col3': ['A', 'B', 'A', 'C', 'B']}
df = pd.DataFrame(data)
categorical_cols = ['col3']
ignore_cols = []
high_corr_features = find_high_correlation_features(df, categorical_cols, ignore_cols, threshold=0.95)
print(high_corr_features)

---

prepare_dataframe_to_ml

Prepares a DataFrame for machine learning by handling categorical and numerical features, missing values, high correlation, and dimensionality reduction using prince.

Parameters:

• df (pd.DataFrame): The input DataFrame.

Returns:

• pd.DataFrame or np.ndarray: A transformed DataFrame or numpy array ready for machine learning. The return type depends on which prince method is used (FAMD, MCA) or if it returns the numerical columns directly.

Example:

import pandas as pd
from utility_pack.ml import prepare_dataframe_to_ml

data = {'col1': [1, 2, 3, 4, 5], 'col2': [2.0, 4.0, 6.0, 8.0, 10.0], 'col3': ['A', 'B', 'A', 'C', 'B']}
df = pd.DataFrame(data)
prepared_df = prepare_dataframe_to_ml(df)
print(prepared_df)

---

recommend_items

Recommends items to sources using Alternating Least Squares (ALS) matrix factorization.

Parameters:

• df (pd.DataFrame): Input DataFrame with 'source', 'item', and 'rating' columns. If 'rating' column is missing then the function will treat all interactions as a positive feedback with rating equals to 1.
• num_factors (int, optional): Number of latent factors. Defaults to 20.
• num_iterations (int, optional): Number of ALS iterations. Defaults to 5.
• reg (float, optional): Regularization parameter. Defaults to 0.1.

Returns:

• pd.DataFrame: DataFrame with columns 'source', 'recommended_item', and 'recommendation_score'.

Example:

import pandas as pd
from utility_pack.ml import recommend_items

data = {'source': ['A', 'A', 'B', 'B', 'C'], 'item': ['X', 'Y', 'X', 'Z', 'Y'], 'rating': [5, 4, 3, 5, 2]}
df = pd.DataFrame(data)
recommendations = recommend_items(df, num_factors=10, num_iterations=3, reg=0.05)
print(recommendations)

sequence_mining_analysis

This script performs sequence mining analysis on transactional data to identify frequent patterns of events.

Parameters:

• df (pd.DataFrame): Input DataFrame containing transactional data.
• id_col (str): Name of the column identifying unique sequences (e.g., customer ID).
• date_col (str): Name of the column containing datetime values representing the order of events.
• analysis_col (str): Name of the column containing the events to be analyzed.

Returns:

• list: A list of dictionaries, where each dictionary contains the 'target' event, its 'antecedents' (previous events), and 'consequents' (subsequent events), along with their probabilities.

Usage Example:

import pandas as pd
from utility_pack.ml import sequence_mining_analysis

# Sample DataFrame
data = {'customer_id': [1, 1, 1, 2, 2, 2],
        'date': ['2023-01-01', '2023-01-02', '2023-01-03', '2023-01-05', '2023-01-06', '2023-01-07'],
        'event': ['A', 'B', 'C', 'B', 'C', 'A']}
df = pd.DataFrame(data)
df['date'] = pd.to_datetime(df['date'])

# Perform sequence mining analysis
results = sequence_mining_analysis(df, 'customer_id', 'date', 'event')

TextClassifier

A class for robust text classification using embeddings and a Multi-layer Perceptron classifier.

Features

• Text embedding using extract_embeddings with both semantic and textual types.
• MLPClassifier for classification.
• Label encoding using LabelEncoder.
• Train/test split.
• Prediction of single texts and batches.
• Saving and loading the classifier.

Usage

from utility_pack.ml import TextClassifier

# Example data
texts = ["This is a positive example", "This is a negative example"]
labels = ["positive", "negative"]

# Initialize and train the classifier
classifier = TextClassifier()
classifier.train(texts, labels)

# Predict a single text
label, probability = classifier.predict("This is another example")
print(f"Predicted label: {label}, Probability: {probability}")

# Predict a batch of texts
predictions = classifier.predict_batch(["example 1", "example 2"])
print(f"Predictions: {predictions}")

# Save the classifier
classifier.save("classifier.pkl")

# Load the classifier
loaded_classifier = TextClassifier.load("classifier.pkl")

---

6. Data Extraction with LLMs (Built-in RAG)

This utility extracts specific data from text using LLMs, with built-in RAG capabilities for large texts. Extracts data from a given text. If the text exceeds the token limit, it uses RAG (Retrieval-Augmented Generation) for efficient extraction.

Parameters:

• full_text (str): The input text to extract data from.
• data_name (str): The name of the data to extract.
• data_description (str): A description of the data to extract.
• llm_provider (LlmProvider): The LLM provider to use (e.g., "openrouter", "ollama", "vllm", "openai").
• llm_model (str): The specific LLM model to use.
• max_input_tokens (int, optional): The maximum number of tokens the LLM can process at once. Defaults to 8192.

Returns:

• str: The extracted data in string format, or None if extraction fails.

Example:

from utility_pack.extraction import get_data_from_text, LlmProvider

text = "..."  # large text
data_name = "email"
data_description = "The email address of the person"

email = get_data_from_text(
    full_text=text,
    data_name=data_name,
    data_description=data_description,
    llm_provider=LlmProvider.OPENROUTER,
    llm_model="mistralai/Mistral-7B-Instruct-v0.2"
)

---

7. FastAPI Wrapper with Built-in Dashboard and bson`s ObjectId fix

This is a fastapi wrapper that encapsulates frequently used functions, such as automatic ObjectId casting to string, telemetry collection, CORS and GZIP middleware as well.

from utility_pack.fastapi_wrapper import FastAPIWrapper
from bson import ObjectId
import uvicorn

# You can provide your own `lifespan`
# The dashboard data and metrics endpoints are also basic-password protected
wrapper = FastAPIWrapper(lifespan=None, username="admin", password="password")
app = wrapper.app

@app.get("/test")
async def test():
    return {"objectid": ObjectId(), "nested": {"objectid": ObjectId()}} # Will cast automatically to str

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=8005)

# Access http://0.0.0.0:8005/api/dashboard to view logged data

---

8. OCR Utility Package

This package provides functions for performing OCR on images, with preprocessing steps for improved accuracy. It includes functionalities for binarization, deskewing, and raw OCR extraction.

To import this module:

from utility_pack.ocr_util import ocr_image_pipeline, raw_ocr_with_topbottom_leftright

ocr_image_pipeline

This function performs a complete OCR pipeline on a PIL image. It includes binarization using Sauvola's method, deskewing, resizing to tesseract's ideal size inference, and extracting text using Tesseract OCR. It prioritizes processing binarized and deskewed images, falling back on the original image if the initial attempt yields no text. It also performs post-processing to remove extra spaces and newline characters. This is the primary function you'll likely use.

from PIL import Image
from utility_pack.ocr_util import ocr_image_pipeline

# Load the image
image_path = 'path/to/your/image.png'  # Replace with your image path
pil_image = Image.open(image_path)

# Perform OCR
text = ocr_image_pipeline(pil_image)

# Print the extracted text
print(text)

raw_ocr_with_topbottom_leftright

This function performs raw OCR extraction on a PIL image or a processed image (like the output of sauvola_binarization or rotate_image), ordering the text by its position on the page (top to bottom, then left to right). It returns the extracted text as a single string, with each line separated by a newline character. It uses pytesseract's image_to_data function to obtain bounding box information and text.

from PIL import Image
from utility_pack.ocr_util import raw_ocr_with_topbottom_leftright

# Load the image
image_path = 'path/to/your/image.png'  # Replace with your image path
pil_image = Image.open(image_path)

# Perform OCR
text = raw_ocr_with_topbottom_leftright(pil_image)

# Print the extracted text
print(text)

9. Pandas Parallelization

This function allows you to parallelize a Pandas DataFrame's apply operation using multiple processes, significantly speeding up computations on large datasets. It leverages cloudpickle to serialize the function, enabling it to be passed between processes safely.

To import this module:

from utility_pack.ocr_util import parallelize_apply

Usage

**parallelize_apply(df, func, n_jobs=-1)**

Applies a function to a Pandas DataFrame in parallel.

• df: The Pandas DataFrame to apply the function to.
• func: The function to apply to each chunk of the DataFrame. The function will receive a Pandas DataFrame chunk as input.
• n_jobs: The number of processes to use. -1 uses all available CPU cores.

import pandas as pd
from utility_pack.ocr_util import parallelize_apply

# Sample DataFrame
data = {'col1': range(100000), 'col2': range(100000, 200000)}
df = pd.DataFrame(data)

# Define a simple function to apply (e.g., square each value in column 'col1')
def square_col1(df_chunk):
    df_chunk['col1_squared'] = df_chunk['col1'] ** 2
    return df_chunk

# Parallelize the apply operation
result_df = parallelize_apply(df.copy(), square_col1, n_jobs=4) # Use 4 processes

# The 'result_df' now contains an additional column 'col1_squared'
print(result_df.head())

10. JSON Parser Utility

This utility provides a function to extract and parse JSON data from strings, handling cases where the JSON is encapsulated within triple backticks or exists as a standalone string.

To import this module:

Finding and Parsing JSON within Triple Backticks

from utility_pack.parsers import find_and_parse_json_from_string

response_string = """
Some surrounding text.
```json
{
  "name": "example",
  "value": 123
}
```
More surrounding text.  
"""

parsed_json = find_and_parse_json_from_string(response_string)  
print(parsed_json)

## Expected Output: {'name': 'example', 'value': 123}

Finding and Parsing Markdown within Triple Backticks

from utility_pack.parsers import extract_markdown_content

response_string = """
Some surrounding text.
```
Hello World
```
More surrounding text.  
"""

parsed_json = extract_markdown_content(response_string)
print(parsed_json)

## Expected Output: Hello World

11. PDF to Text Extraction with OCR Strategies

This module provides functionality to extract text from PDF files, with options to control OCR execution based on different strategies. It leverages the fitz (PyMuPDF) library for PDF processing and PIL for image manipulation and a custom ocr_image_pipeline for OCR.

To import this module:

from utility_pack.pdfs import pdf_to_text, OcrStrategy

Extract Text from PDF

The pdf_to_text function is the primary entry point for extracting text. It accepts a PDF file path and an OCR strategy to determine when to apply OCR.

from utility_pack.pdfs import pdf_to_text, OcrStrategy

filepath = "path/to/your/pdf_file.pdf"  # Replace with the actual path to your PDF file
result = pdf_to_text(filepath, strategy_ocr=OcrStrategy.Auto)

print(result['full_text'])

OCR Strategies

The OcrStrategy Enum defines the available strategies for handling OCR.

• Always: OCR is performed on every page.
• Never: OCR is never performed. Extracts only text that is already in the text layer of the PDF (if any).
• Auto: OCR is performed on pages which have less then 10 words already extracted from their vectorized text, or detected as photos.

from utility_pack.pdfs import pdf_to_text, OcrStrategy

filepath = "path/to/your/pdf_file.pdf"

# Example using the 'Always' strategy:
result = pdf_to_text(filepath, strategy_ocr=OcrStrategy.Always)
print(result['full_text'])

Customize Zoom Factor

The zoom_factor parameter in pdf_to_text and get_pdf_page_as_image functions allows customization of the resolution of the converted image before OCR is performed. Higher values means more pixels and potentially better OCR results, at the cost of performance.

from utility_pack.pdfs import pdf_to_text, OcrStrategy

filepath = "path/to/your/pdf_file.pdf"
result = pdf_to_text(filepath, strategy_ocr=OcrStrategy.Auto, zoom_factor=4.0) # Setting zoom to 4.0
print(result['full_text'])

Get a PDF Page as an Image

The get_pdf_page_as_image function converts a specific page of a PDF into a PIL image object (via a PixMap object from pymupdf). This allows you to get image representations of specific pdf pages, which are used as inputs to the OCR process.

from utility_pack.pdfs import get_pdf_page_as_image

filepath = "path/to/your/pdf_file.pdf"
page_number = 0 # first page

pix_image = get_pdf_page_as_image(filepath, page_number)
print(type(pix_image))

Determine if a page is a photo

The is_photo function determines if a pix_image contains a photo based on the amount of white pixels.

from utility_pack.pdfs import get_pdf_page_as_image, is_photo

filepath = "path/to/your/pdf_file.pdf"
page_number = 0

pix_image = get_pdf_page_as_image(filepath, page_number)
is_it_a_photo = is_photo(pix_image)
print(is_it_a_photo)

12. Text Utilities

This module provides a collection of text processing and utility functions for tasks such as cleaning, compressing, comparing, and chunking text.

Usage

Import functions and classes as follows:

from utility_pack.text import (
    get_uuid,
    remove_stopwords,
    remove_accents_replace,
    remove_accents_completely,
    remove_special_characters,
    remove_asian_characters,
    remove_html_tags,
    cleanup_markdown,
    remove_extra_whitespace,
    remove_numbers,
    remove_urls,
    remove_emails,
    compress_text,
    StringSimilarity,
    string_similarity,
    string_similarity_from_list,
    find_needle_in_haystack,
    chunk_text
)

Here separated single examples of each available module functionality

get_uuid

Generates a short UUID.

from utility_pack.text import get_uuid
unique_id = get_uuid()
print(unique_id)

remove_stopwords

Removes common English (default) or Portuguese stopwords from a string.

from utility_pack.text import remove_stopwords
text = "This is an example sentence with some stopwords."
cleaned_text = remove_stopwords(text)
print(cleaned_text)  # Output: example sentence stopwords.

remove_accents_replace

Removes accents by replacing accented characters with their base characters.

from utility_pack.text import remove_accents_replace
text = "Êxèmplo çøm áçêntøs."
cleaned_text = remove_accents_replace(text)
print(cleaned_text)  # Output: Exemplo com acentos.

remove_accents_completely

Removes accents entirely, deleting accented characters.

from utility_pack.text import remove_accents_completely
text = "Êxèmplo çøm áçêntøs."
cleaned_text = remove_accents_completely(text)
print(cleaned_text)  # Output: Exmplo cm cnts.

remove_special_characters

Removes special characters, leaving only alphanumeric characters and spaces.

from utility_pack.text import remove_special_characters
text = "Hello! This is a [e-mail]."
cleaned_text = remove_special_characters(text)
print(cleaned_text)  # Output: Hello This is a testexamplecom

remove_asian_characters

Removes Asian characters from the given string.

from utility_pack.text import remove_asian_characters
text = "Hello こんにちは 世界"
cleaned_text = remove_asian_characters(text)
print(cleaned_text) # Output: Hello

remove_html_tags

Removes HTML tags from a string.

from utility_pack.text import remove_html_tags
text = "<p>This is <b>bold</b> text.</p>"
cleaned_text = remove_html_tags(text)
print(cleaned_text)  # Output: This is bold text.

cleanup_markdown

Converts Markdown to plain text by removing Markdown formatting.

from utility_pack.text import cleanup_markdown
text = "# This is a heading\n* This is a list item"
cleaned_text = cleanup_markdown(text)
print(cleaned_text)
# Output:
# This is a heading
# This is a list item

remove_extra_whitespace

Removes extra whitespace, leaving only single spaces between words.

from utility_pack.text import remove_extra_whitespace
text = "  This   has   extra    spaces.  "
cleaned_text = remove_extra_whitespace(text)
print(cleaned_text)  # Output: This has extra spaces.

remove_numbers

Removes all numeric characters from the string.

from utility_pack.text import remove_numbers
text = "This is a test string with 123 numbers."
cleaned_text = remove_numbers(text)
print(cleaned_text)  # Output: This is a test string with  numbers.

remove_urls

Removes URLs from a string.

from utility_pack.text import remove_urls
text = "Visit my website at https://www.example.com."
cleaned_text = remove_urls(text)
print(cleaned_text)  # Output: Visit my website at .

remove_emails

Removes email addresses from a string.

from utility_pack.text import remove_emails
text = "Contact me at [e-mail]."
cleaned_text = remove_emails(text)
print(cleaned_text)  # Output: Contact me at .

compress_text

Compresses text using semantic compression. Requires compressor package to be installed.

from utility_pack.text import compress_text
text = "This is a long sentence that will be compressed."
compressed_text = compress_text(text, compression_rate=0.7)
print(compressed_text)

string_similarity

Calculates the similarity between two strings using fuzzy matching based on Enum StringSimilarity.

from utility_pack.text import string_similarity, StringSimilarity
string1 = "apple"
string2 = "aplle"
similarity = string_similarity(string1, string2, method=StringSimilarity.Ratio)
print(similarity)  # Output: e.g. 80

string_similarity_from_list

Calculates the similarity between a reference string and a list of strings, and returns the most similar string (or top N most similar).

from utility_pack.text import string_similarity_from_list
reference_string = "apple"
list_of_strings = ["aplle", "banana", "orange"]
result = string_similarity_from_list(reference_string, list_of_strings)
print(result)  # Output: ('aplle', 80) (example value)

find_needle_in_haystack

Reranks documents to find the "needle" (best match) in a "haystack" (list of documents) using a combination of textual and semantic reranking.

from utility_pack.text import find_needle_in_haystack
needle = "What is the capital of France?"
haystack = [
    "Paris is the capital of France.",
    "London is the capital of England.",
    "France is a country in Europe."
]
result = find_needle_in_haystack(needle, haystack)
print(result)

chunk_text

Splits text into chunks of specified token count with optional overlap.

from utility_pack.text import chunk_text
text = "This is a long piece of text that needs to be chunked."
chunks = chunk_text(text, chunk_token_count=10, overlap=2)
print(chunks)

13. Vector Databases

This library provides two classes for vector storage and retrieval: MiniVectorDB for lightweight, in-memory storage with metadata filtering, and VectorDB for scalable, production-ready storage using MongoDB and LMDB.

MiniVectorDB

MiniVectorDB offers a simple, file-based vector database with metadata filtering capabilities. It uses pickle for storage and Faiss for indexing.

from utility_pack.vector_storage import MiniVectorDB
import numpy as np

# Initialize a MiniVectorDB instance
db = MiniVectorDB(storage_file='my_vector_db.pkl')

Store a single embedding

unique_id = "doc1"
embedding = np.array([0.1, 0.2, 0.3], dtype=np.float32)
metadata = {"category": "science", "author": "John Doe"}

db.store_embedding(unique_id, embedding, metadata)

Store a batch of embeddings

unique_ids = ["doc2", "doc3"]
embeddings = [
    np.array([0.4, 0.5, 0.6], dtype=np.float32),
    np.array([0.7, 0.8, 0.9], dtype=np.float32)
]
metadata_dicts = [
    {"category": "history", "author": "Jane Smith"},
    {"category": "technology", "author": "Peter Jones"}
]

db.store_embeddings_batch(unique_ids, embeddings, metadata_dicts)

Get a vector by its unique ID

unique_id = "doc1"
vector = db.get_vector(unique_id)
print(vector)

Delete an embedding

unique_id = "doc1"
db.delete_embedding(unique_id)

Find the most similar embeddings (Semantic Search)

query_embedding = np.array([0.2, 0.3, 0.4], dtype=np.float32)
metadata_filter = {"category": "science"}
exclude_filter = {"author": "John Doe"}
or_filters = [{"category": "science"}, {"author": "Jane Smith"}]

ids, distances, metadatas = db.find_most_similar(query_embedding, metadata_filter=metadata_filter, exclude_filter=exclude_filter, or_filters=or_filters, k=3)

print(f"IDs: {ids}")
print(f"Distances: {distances}")
print(f"Metadatas: {metadatas}")

Persist the database to disk

db.persist_to_disk()

VectorDB

VectorDB is designed for production environments, integrating MongoDB for metadata storage and LMDB for efficient vector storage. It depends on the ShardedLmdbStorage helper class for LMDB management. From utility_pack.vector_storage_helper import ShardedLmdbStorage

from utility_pack.vector_storage_helper import ShardedLmdbStorage
from utility_pack.vector_storage import VectorDB

# Initialize ShardedLmdbStorage. Ensure to provide lmdb_dir at init
vector_storage = ShardedLmdbStorage(base_path="shards/vectors", num_shards=5)
text_storage = ShardedLmdbStorage(base_path="shards/texts", num_shards=5)

db = VectorDB(mongo_uri="mongodb://localhost:27017/", mongo_database="my_db", mongo_collection="my_collection", vector_storage=vector_storage, text_storage=text_storage)

Store a batch of embeddings with metadata and text

unique_ids = ["doc1", "doc2"]
embeddings = [
    np.array([0.1, 0.2, 0.3], dtype=np.float32),
    np.array([0.4, 0.5, 0.6], dtype=np.float32)
]
metadata_dicts = [
    {"category": "science", "author": "John Doe", "text_content": "This is a science document."},
    {"category": "history", "author": "Jane Smith", "text_content": "This is a history document."}
]

db.store_embeddings_batch(unique_ids, embeddings, metadata_dicts=metadata_dicts, text_field="text_content")

Delete embeddings by unique IDs

unique_ids = ["doc1", "doc2"]
db.delete_embeddings_batch(unique_ids)

Delete embeddings based on metadata

metadata_filters = {"category": "science"}
db.delete_embeddings_by_metadata(metadata_filters)

Find the most similar embeddings (basic usage)

query_embedding = np.array([0.2, 0.3, 0.4], dtype=np.float32)
filters = {"category": "science"}
output_fields = ["author"]

ids, distances, metadatas = db.find_most_similar(query_embedding, filters=filters, output_fields=output_fields, k=3)

print(f"IDs: {ids}")
print(f"Distances: {distances}")
print(f"Metadatas: {metadatas}")

Find the most similar embeddings with batch processing

query_embedding = np.array([0.2, 0.3, 0.4], dtype=np.float32)
filters = {"category": "science"}
output_fields = ["author"]

ids, distances, metadatas = db.find_most_similar_in_batches(query_embedding, filters=filters, output_fields=output_fields, k=3, max_ram_usage_gb=1)

print(f"IDs: {ids}")
print(f"Distances: {distances}")
print(f"Metadatas: {metadatas}")

Check the count for each of the storages

db.check_counts()

total_count = db.get_total_count()
print(f"Total count of documents: {total_count}")