fenic

fenic is a PySpark-inspired DataFrame framework designed for building production AI and agentic applications. fenic provides support for reading datasets directly from the Hugging Face Hub.

Getting Started

To get started, pip install fenic:

pip install fenic

Create a Session

Instantiate a fenic session with the default configuration (sufficient for reading datasets and other non-semantic operations):

import fenic as fc

session = fc.Session.get_or_create(fc.SessionConfig())

Overview

fenic is an opinionated data processing framework that combines:

Read from Hugging Face Hub

fenic can read datasets directly from the Hugging Face Hub using the hf:// protocol. This functionality is built into fenic’s DataFrameReader interface.

Supported Formats

fenic supports reading the following formats from Hugging Face:

Reading Datasets

To read a dataset from the Hugging Face Hub:

import fenic as fc

session = fc.Session.get_or_create(fc.SessionConfig())

# Read a CSV file from a public dataset
df = session.read.csv("hf://datasets/datasets-examples/doc-formats-csv-1/data.csv")

# Read Parquet files using glob patterns
df = session.read.parquet("hf://datasets/cais/mmlu/astronomy/*.parquet")

# Read from a specific dataset revision
df = session.read.parquet("hf://datasets/datasets-examples/doc-formats-csv-1@~parquet/**/*.parquet")

Reading with Schema Management

# Read multiple CSV files with schema merging
df = session.read.csv("hf://datasets/username/dataset_name/*.csv", merge_schemas=True)

# Read multiple Parquet files with schema merging
df = session.read.parquet("hf://datasets/username/dataset_name/*.parquet", merge_schemas=True)

Note: In fenic, a schema is the set of column names and their data types. When you enable merge_schemas, fenic tries to reconcile differences across files by filling missing columns with nulls and widening types where it can. Some layouts still cannot be merged—consult the fenic docs for CSV schema merging limitations and Parquet schema merging limitations.

Authentication

To read private datasets, you need to set your Hugging Face token as an environment variable:

export HF_TOKEN="your_hugging_face_token_here"

Path Format

The Hugging Face path format in fenic follows this structure:

hf://{repo_type}/{repo_id}/{path_to_file}

You can also specify dataset revisions or versions:

hf://{repo_type}/{repo_id}@{revision}/{path_to_file}

Features:

Mixing Data Sources

fenic allows you to combine multiple data sources in a single read operation, including mixing different protocols:

# Mix HF and local files in one read call
df = session.read.parquet([
    "hf://datasets/cais/mmlu/astronomy/*.parquet",
    "file:///local/data/*.parquet",
    "./relative/path/data.parquet"
])

This flexibility allows you to seamlessly combine data from Hugging Face Hub and local files in your data processing pipeline.

Processing Data from Hugging Face

Once loaded from Hugging Face, you can use fenic’s full DataFrame API:

Basic DataFrame Operations

import fenic as fc

session = fc.Session.get_or_create(fc.SessionConfig())

# Load IMDB dataset from Hugging Face
df = session.read.parquet("hf://datasets/imdb/plain_text/train-*.parquet")

# Filter and select
positive_reviews = df.filter(fc.col("label") == 1).select("text", "label")

# Group by and aggregate
label_counts = df.group_by("label").agg(
    fc.count("*").alias("count")
)

AI-Powered Operations

To use semantic and embedding operations, configure language and embedding models in your SessionConfig. Once configured:

import fenic as fc

# Requires OPENAI_API_KEY to be set for language and embedding calls
session = fc.Session.get_or_create(
    fc.SessionConfig(
        semantic=fc.SemanticConfig(
            language_models={
                "gpt-4o-mini": fc.OpenAILanguageModel(
                    model_name="gpt-4o-mini",
                    rpm=60,
                    tpm=60000,
                )
            },
            embedding_models={
                "text-embedding-3-small": fc.OpenAIEmbeddingModel(
                    model_name="text-embedding-3-small",
                    rpm=60,
                    tpm=60000,
                )
            },
        )
    )
)

# Load a text dataset from Hugging Face
df = session.read.parquet("hf://datasets/imdb/plain_text/train-00000-of-00001.parquet")

# Add embeddings to text columns
df_with_embeddings = df.select(
    "*",
    fc.semantic.embed(fc.col("text")).alias("embedding")
)

# Apply semantic functions for sentiment analysis
df_analyzed = df_with_embeddings.select(
    "*",
    fc.semantic.analyze_sentiment(
        fc.col("text"),
        model_alias="gpt-4o-mini",  # Optional: specify model
    ).alias("sentiment")
)

Example: Analyzing MMLU Dataset

import fenic as fc

# Requires OPENAI_API_KEY to be set for semantic calls
session = fc.Session.get_or_create(
    fc.SessionConfig(
        semantic=fc.SemanticConfig(
            language_models={
                "gpt-4o-mini": fc.OpenAILanguageModel(
                    model_name="gpt-4o-mini",
                    rpm=60,
                    tpm=60000,
                )
            },
        )
    )
)

# Load MMLU astronomy subset from Hugging Face
df = session.read.parquet("hf://datasets/cais/mmlu/astronomy/*.parquet")

# Process the data
processed_df = (df
    # Filter for specific criteria
    .filter(fc.col("subject") == "astronomy")
    # Select relevant columns
    .select("question", "choices", "answer")
    # Add difficulty analysis using semantic.map
    .select(
        "*",
        fc.semantic.map(
            "Rate the difficulty of this question from 1-5: {{question}}",
            question=fc.col("question"),
            model_alias="gpt-4o-mini"  # Optional: specify model
        ).alias("difficulty")
    )
)

# Show results
processed_df.show()

Resources

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