User Guide

This guide provides in-depth coverage of each eftoolkit module.

Modules Overview

Module	Primary Class	Description
eftoolkit.sql	DuckDB	SQL queries with DuckDB, S3 integration
eftoolkit.s3	S3FileSystem	S3 operations for parquet files
eftoolkit.gsheets	Spreadsheet, Worksheet	Google Sheets with batching
eftoolkit.config	Functions	JSON loading, logging setup

Design Principles

Consistency

All modules follow similar patterns:

• Explicit credential/configuration in __init__
• Context manager support where appropriate
• DataFrame-centric data handling
• Clear error messages

Minimal Abstraction

eftoolkit provides thin wrappers that:

• Don't hide the underlying libraries (DuckDB, gspread, boto3)
• Allow direct access to native APIs when needed
• Add convenience methods for common operations

S3 URI Convention

S3 paths use the standard URI format throughout:

s3://bucket-name/path/to/file.parquet

Both DuckDB and S3FileSystem understand this format.

Quick Links

• DuckDB Wrapper - SQL queries, table creation, S3 integration
• S3 Operations - Parquet read/write, file operations, listing
• Google Sheets - Batched operations, formatting, local preview
• Configuration - JSON/JSONC loading, logging setup