# Ghosttypes Pokemon Go MCP Mypy > Mypy - Professional Static Type Checking - Skill: `tomevault-io/ghosttypes-pokemon-go-mcp-mypy` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/ghosttypes-pokemon-go-mcp-mypy` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/ghosttypes-pokemon-go-mcp-mypy/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/ghosttypes-pokemon-go-mcp-mypy --- # Mypy - Professional Static Type Checking Mypy is a static type checker for Python that finds bugs without running code. This skill provides comprehensive guidance for professional mypy integration and usage. ## Quick Start ### Installation and Basic Usage ```bash # Install mypy python3 -m pip install mypy # Check a file mypy program.py # Check with strict mode mypy --strict program.py ``` ### Basic Type Annotations ```python def greeting(name: str) -> str: return 'Hello ' + name # Type checking catches errors greeting(3) # Error: Argument has incompatible type "int"; expected "str" ``` ## Configuration Mypy supports multiple configuration formats (discovery order): 1. `mypy.ini` 2. `.mypy.ini` 3. `pyproject.toml` (with `[tool.mypy]` section) 4. `setup.cfg` (with `[mypy]` section) ### Essential Configuration Options ```ini # mypy.ini [mypy] python_version = 3.11 warn_return_any = True warn_unused_configs = True disallow_untyped_defs = True # Per-module configuration [mypy-module_name.*] ignore_missing_imports = True ``` See `references/config_file.md` for complete configuration reference. ## Core Workflows ### Adding Types to Existing Code 1. Start with `--check-untyped-defs` for gradual typing 2. Use `# type: ignore` comments sparingly for temporary exceptions 3. Add type annotations incrementally, module by module 4. Enable stricter checks progressively See `references/existing_code.md` for migration strategies. ### Resolving Type Errors When mypy reports errors: 1. Check the error code (e.g., `[attr-defined]`) 2. Consult error code documentation: - `references/error_code_list.md` - Default errors - `references/error_code_list2.md` - Optional checks 3. Use type narrowing techniques when needed 4. Consider `reveal_type()` for debugging type inference See `references/common_issues.md` for troubleshooting. ### Working with Advanced Types **Generics**: `references/generics.md` - TypeVar, Generic classes, bounded type variables - Variance (covariant, contravariant, invariant) **Protocols**: `references/protocols.md` - Structural subtyping, runtime checkable protocols - Protocol composition **TypedDict**: `references/typed_dict.md` - Required vs optional keys, inheritance - Total vs non-total TypedDicts **Literal Types**: `references/literal_types.md` - String/int/bool/Enum literals - Exhaustiveness checking See `references/kinds_of_types.md` for type system overview. ## Command Line Reference ```bash # Strict mode (recommended for new projects) mypy --strict module.py # Check specific paths mypy src/ tests/ # Generate HTML coverage report mypy --html-report ./mypy-report src/ # Use mypy daemon for faster checking dmypy run -- src/ # Generate stubs from existing code stubgen -p mypackage -o stubs/ ``` See `references/command_line.md` for all CLI options. ## CI/CD Integration ### GitHub Actions Example ```yaml - name: Type check with mypy run: | pip install mypy mypy --install-types --non-interactive mypy src/ ``` ### Pre-commit Hook ```yaml # .pre-commit-config.yaml repos: - repo: https://github.com/pre-commit/mirrors-mypy rev: v1.19.1 hooks: - id: mypy additional_dependencies: [types-all] ``` ## Reference Documentation The `references/` directory contains complete mypy 1.19.1 documentation: ### Getting Started - `getting_started.md` - Installation, basic concepts - `cheat_sheet_py3.md` - Quick reference guide ### Type System - `builtin_types.md` - Python built-in types - `type_inference_and_annotations.md` - Annotations guide - `kinds_of_types.md` - Type system overview - `class_basics.md` - Class typing fundamentals - `protocols.md` - Structural subtyping - `generics.md` - Generic types and TypeVars - `typed_dict.md` - TypedDict patterns - `literal_types.md` - Literal types and Enums - `final_attrs.md` - Final declarations - `more_types.md` - Additional type patterns - `type_narrowing.md` - Type narrowing techniques - `duck_type_compatibility.md` - Duck typing rules ### Configuration & Running - `config_file.md` - Complete configuration reference - `command_line.md` - CLI options and flags - `running_mypy.md` - Running mypy guide - `inline_config.md` - Inline type comments - `mypy_daemon.md` - Daemon mode for speed - `installed_packages.md` - Package type stubs ### Advanced Topics - `stubs.md` - Stub files guide - `stubgen.md` - Automatic stub generation - `stubtest.md` - Stub testing tool - `extending_mypy.md` - Plugins and extensions - `metaclasses.md` - Metaclass typing - `runtime_troubles.md` - Runtime annotation issues - `dynamic_typing.md` - Dynamic typing patterns ### Troubleshooting - `error_codes.md` - Error code system - `error_code_list.md` - Default error codes - `error_code_list2.md` - Optional error codes - `common_issues.md` - Solutions to common issues - `faq.md` - Frequently asked questions ### Project Info - `additional_features.md` - Advanced features - `supported_python_features.md` - Python version support - `existing_code.md` - Migration strategies - `changelog.md` - Version history ## Updating Documentation The `scripts/` directory contains tools to refresh documentation from mypy.readthedocs.io: ```bash # Discover all documentation pages python scripts/discover_pages.py > mypy_pages.txt # Bulk scrape and clean documentation python scripts/scrape_docs.py # Clean individual markdown files python scripts/clean_markdown.py input.md output.md ``` These scripts use cloudscraper for Cloudflare bypass and automatically clean navigation/footer content. ## Best Practices 1. **Start gradually** - Use `--check-untyped-defs` initially 2. **Configure per-module** - Different strictness for different parts of codebase 3. **Use error codes** - Specific `# type: ignore[code]` instead of blanket ignores 4. **Leverage inference** - Let mypy infer types when obvious 5. **Run in CI** - Catch type errors before merge 6. **Update regularly** - Stay current with mypy releases for better type checking ## Common Patterns ### Optional Values ```python from typing import Optional def find_user(id: int) -> Optional[User]: # May return None return user_db.get(id) ``` ### Union Types ```python from typing import Union def process(value: Union[int, str]) -> str: if isinstance(value, int): return str(value) return value ``` ### Generic Functions ```python from typing import TypeVar, Sequence T = TypeVar('T') def first(seq: Sequence[T]) -> T: return seq[0] ``` ### Protocol (Structural Typing) ```python from typing import Protocol class Drawable(Protocol): def draw(self) -> None: ... def render(obj: Drawable) -> None: obj.draw() # Any object with draw() works ``` ## Version Information This skill is based on mypy 1.19.1 (stable) documentation. Use the scraping scripts to update to newer versions as they are released. --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/ghosttypes) — claim your Tome and manage your conversions.