adding Claude.md

Author: seperman

CLAUDE.md

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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+DeepDiff is a Python library for deep comparison, searching, and hashing of Python objects. It provides:
+- **DeepDiff**: Deep difference detection between objects
+- **DeepSearch**: Search for objects within other objects  
+- **DeepHash**: Content-based hashing for any object
+- **Delta**: Git-like diff objects that can be applied to other objects
+- **CLI**: Command-line interface via `deep` command
+
+## Development Commands
+
+### Setup
+```bash
+# Install with all development dependencies
+pip install -e ".[cli,coverage,dev,docs,static,test]"
+# OR using uv (recommended)
+uv sync --all-extras
+```
+
+### Testing
+```bash
+# Run tests with coverage
+pytest --cov=deepdiff --cov-report term-missing
+
+# Run tests including slow ones
+pytest --cov=deepdiff --runslow
+
+# Run single test file
+pytest tests/test_diff_text.py
+
+# Run tests across multiple Python versions
+nox -s pytest
+```
+
+### Quality Checks
+```bash
+# Linting (max line length: 120)
+nox -s flake8
+
+# Type checking
+nox -s mypy
+
+# Run all quality checks
+nox
+```
+
+## Architecture
+
+### Core Structure
+- **deepdiff/diff.py**: Main DeepDiff implementation (most complex component)
+- **deepdiff/deephash.py**: DeepHash functionality
+- **deepdiff/base.py**: Shared base classes and functionality
+- **deepdiff/model.py**: Core data structures and result objects
+- **deepdiff/helper.py**: Utility functions and type definitions
+- **deepdiff/delta.py**: Delta objects for applying changes
+
+### Key Patterns
+- **Inheritance**: `Base` class provides common functionality with mixins
+- **Result Objects**: Different result formats (`ResultDict`, `TreeResult`, `TextResult`)
+- **Path Navigation**: Consistent path notation for nested object access
+- **Performance**: LRU caching and numpy array optimization
+
+### Testing
+- Located in `/tests/` directory
+- Organized by functionality (e.g., `test_diff_text.py`, `test_hash.py`)
+- Aims for ~100% test coverage
+- Uses pytest with comprehensive fixtures
+
+## Development Notes
+
+- **Python Support**: 3.9+ and PyPy3
+- **Main Branch**: `master` (PRs typically go to `dev` branch)
+- **Build System**: Modern `pyproject.toml` with `flit_core`
+- **Dependencies**: Core dependency is `orderly-set>=5.4.1,<6`
+- **CLI Tool**: Available as `deep` command after installation with `[cli]` extra