Add TapIgnore

README.md

@@ -41,16 +41,16 @@ Running `python square.py --num 2` will print `The square of your number is 4.0.
 
 Tap requires Python 3.10+
 
-To install Tap from PyPI run: 
+To install Tap from PyPI run:
 
-```
+```shell
 pip install typed-argument-parser
 ```
 
 <details>
 <summary>To install Tap from source, run the following commands:</summary>
 
-```
+```shell
 git clone https://github.com/swansonk14/typed-argument-parser.git
 cd typed-argument-parser
 pip install -e .
@@ -61,51 +61,69 @@ pip install -e .
 <details>
 <summary>To develop this package, install development requirements (in a virtual environment):</summary>
 
-```
+```shell
 python -m pip install -e ".[dev]"
 ```
 
 Use [`flake8`](https://github.com/PyCQA/flake8) linting.
 
 To run tests, run:
 
-```
+```shell
 pytest
 ```
 
 </details>
 
 ## Table of Contents
 
-* [Installation](#installation)
-* [Table of Contents](#table-of-contents)
-* [Tap is Python-native](#tap-is-python-native)
-* [Tap features](#tap-features)
-  + [Arguments](#arguments)
-  + [Tap help](#tap-help)
-  + [Configuring arguments](#configuring-arguments)
-    - [Adding special argument behavior](#adding-special-argument-behavior)
-    - [Adding subparsers](#adding-subparsers)
-  + [Types](#types)
-  + [Argument processing](#argument-processing)
-  + [Processing known args](#processing-known-args)
-  + [Subclassing](#subclassing)
-  + [Printing](#printing)
-  + [Reproducibility](#reproducibility)
-  + [Saving and loading arguments](#saving-and-loading-arguments)
-  + [Loading from configuration files](#loading-from-configuration-files)
-* [tapify](#tapify)
-  + [Examples](#examples)
-    - [Function](#function)
-    - [Class](#class)
-    - [Dataclass](#dataclass)
-  + [tapify help](#tapify-help)
-  + [Command line vs explicit arguments](#command-line-vs-explicit-arguments)
-  + [Known args](#known-args)
-* [Convert to a `Tap` class](#convert-to-a-tap-class)
-  + [`to_tap_class` examples](#to_tap_class-examples)
-    - [Simple](#simple)
-    - [Complex](#complex)
+- [Typed Argument Parser (Tap)](#typed-argument-parser-tap)
+  - [Installation](#installation)
+  - [Table of Contents](#table-of-contents)
+  - [Tap is Python-native](#tap-is-python-native)
+  - [Tap features](#tap-features)
+    - [Arguments](#arguments)
+    - [Tap help](#tap-help)
+    - [Configuring arguments](#configuring-arguments)
+      - [Adding special argument behavior](#adding-special-argument-behavior)
+      - [Adding subparsers](#adding-subparsers)
+    - [Types](#types)
+      - [`str`, `int`, and `float`](#str-int-and-float)
+      - [`bool`](#bool)
+      - [`Optional`](#optional)
+      - [`List`](#list)
+      - [`Set`](#set)
+      - [`Tuple`](#tuple)
+      - [`Literal`](#literal)
+      - [`Union`](#union)
+      - [Complex Types](#complex-types)
+    - [Ignore Attribute](#ignore-attribute)
+    - [Argument processing](#argument-processing)
+    - [Processing known args](#processing-known-args)
+    - [Subclassing](#subclassing)
+    - [Printing](#printing)
+    - [Reproducibility](#reproducibility)
+      - [Reproducibility info](#reproducibility-info)
+    - [Conversion Tap to and from dictionaries](#conversion-tap-to-and-from-dictionaries)
+    - [Saving and loading arguments](#saving-and-loading-arguments)
+      - [Save](#save)
+      - [Load](#load)
+      - [Load from dict](#load-from-dict)
+    - [Loading from configuration files](#loading-from-configuration-files)
+  - [tapify](#tapify)
+    - [Examples](#examples)
+      - [Function](#function)
+      - [Class](#class)
+      - [Dataclass](#dataclass)
+      - [Pydantic](#pydantic)
+    - [tapify help](#tapify-help)
+    - [Command line vs explicit arguments](#command-line-vs-explicit-arguments)
+    - [Known args](#known-args)
+    - [Explicit boolean arguments](#explicit-boolean-arguments)
+  - [Convert to a `Tap` class](#convert-to-a-tap-class)
+    - [`to_tap_class` examples](#to_tap_class-examples)
+      - [Simple](#simple)
+      - [Complex](#complex)
 
 ## Tap is Python-native
 
@@ -361,6 +379,33 @@ args = Args().parse_args('--aged_person Tapper,27'.split())
 print(f'{args.aged_person.name} is {args.aged_person.age}')  # Tapper is 27
 ```
 
+### Ignore Attribute
+
+Sometimes you may want to define attributes that should not be parsed as command line arguments, but you still want to type them.
+This can be achieved by using `TapIgnore`.
+
+```python
+from tap import Tap, TapIgnore
+
+class MyTap(Tap):
+    # Regular arguments (will be parsed)
+    package: str
+    stars: int = 5
+
+    # Ignored attributes (will not be parsed)
+    internal_counter: TapIgnore[int] = 0
+
+args = MyTap().parse_args(["--help"])
+```
+
+```txt
+usage: ipython --package PACKAGE [--stars STARS] [-h]
+
+options:
+  --package PACKAGE  (str, required)
+  --stars STARS      (int, default=5)
+  -h, --help         show this help message and exit
+```
 
 ### Argument processing
 
@@ -863,7 +908,7 @@ Running `python person.py --name Jesse --age 1` prints `My name is Jesse.` follo
 
 ### Explicit boolean arguments
 
-Tapify supports explicit specification of boolean arguments (see [bool](#bool) for more details). By default, `explicit_bool=False` and it can be set with `tapify(..., explicit_bool=True)`. 
+Tapify supports explicit specification of boolean arguments (see [bool](#bool) for more details). By default, `explicit_bool=False` and it can be set with `tapify(..., explicit_bool=True)`.
 
 ## Convert to a `Tap` class
 
@@ -903,7 +948,7 @@ if __name__ == "__main__":
 
 Running `python main.py --package tap` will print `Project instance: package='tap' is_cool=True stars=5`.
 
-### Complex
+#### Complex
 
 The general pattern is:
 

src/tap/__init__.py

@@ -5,13 +5,16 @@
 __version__ = "1.11.0"
 
 from argparse import ArgumentError, ArgumentTypeError
+
 from tap.tap import Tap
 from tap.tapify import tapify, to_tap_class
+from tap.utils import TapIgnore
 
 __all__ = [
     "ArgumentError",
     "ArgumentTypeError",
     "Tap",
+    "TapIgnore",
     "tapify",
     "to_tap_class",
     "__version__",

src/tap/tap.py

@@ -8,7 +8,22 @@
 from pprint import pformat
 from shlex import quote, split
 from types import MethodType, UnionType
-from typing import Any, Callable, Iterable, List, Optional, Sequence, Set, Tuple, TypeVar, Union, get_type_hints
+from typing import (
+    Annotated,
+    Any,
+    Callable,
+    Iterable,
+    List,
+    Optional,
+    Sequence,
+    Set,
+    Tuple,
+    TypeVar,
+    Union,
+    get_type_hints,
+    get_origin as typing_get_origin,
+    get_args as typing_get_args,
+)
 from typing_inspect import is_literal_type
 
 from tap.utils import (
@@ -23,6 +38,7 @@
     type_to_str,
     get_literals,
     boolean_type,
+    _TapIgnoreMarker,
     TupleTypeEnforcer,
     define_python_object_encoder,
     as_python_object,
@@ -92,6 +108,7 @@ def __init__(
 
         # Get annotations from self and all super classes up through tap
         self._annotations = self._get_annotations()
+        self._annotations_with_extras = self._get_annotations(include_extras=True)
 
         # Set the default description to be the docstring
         kwargs.setdefault("description", self.__doc__)
@@ -300,10 +317,21 @@ def add_argument(self, *name_or_flags, **kwargs) -> None:
         variable = get_argument_name(*name_or_flags).replace("-", "_")
         self.argument_buffer[variable] = (name_or_flags, kwargs)
 
+    def _is_ignored_argument(self, variable: str, annotations: Optional[dict[str, Any]] = None) -> bool:
+        annotations = self._annotations_with_extras if annotations is None else annotations
+        if variable in annotations:
+            var_type = annotations[variable]
+            if typing_get_origin(var_type) is Annotated and _TapIgnoreMarker in typing_get_args(var_type):
+                return True
+        return False
+
     def _add_arguments(self) -> None:
         """Add arguments to self in the order they are defined as class variables (so the help string is in order)."""
         # Add class variables (in order)
         for variable in self.class_variables:
+            if self._is_ignored_argument(variable):
+                continue
+
             if variable in self.argument_buffer:
                 name_or_flags, kwargs = self.argument_buffer[variable]
                 self._add_argument(*name_or_flags, **kwargs)
@@ -313,6 +341,8 @@ def _add_arguments(self) -> None:
         # Add any arguments that were added manually in configure but aren't class variables (in order)
         for variable, (name_or_flags, kwargs) in self.argument_buffer.items():
             if variable not in self.class_variables:
+                if self._is_ignored_argument(variable):
+                    continue
                 self._add_argument(*name_or_flags, **kwargs)
 
     def process_args(self) -> None:
@@ -483,7 +513,7 @@ def parse_args(
         return self
 
     @classmethod
-    def _get_from_self_and_super(cls, extract_func: Callable[[type], dict]) -> dict[str, Any] | dict:
+    def _get_from_self_and_super(cls, extract_func: Callable[[type], dict]) -> dict[str, Any]:
         """Returns a dictionary mapping variable names to values.
 
         Variables and values are extracted from classes using key starting
@@ -531,11 +561,16 @@ def _get_class_dict(self) -> dict[str, Any]:
 
         return class_dict
 
-    def _get_annotations(self) -> dict[str, Any]:
-        """Returns a dictionary mapping variable names to their type annotations."""
-        return self._get_from_self_and_super(extract_func=lambda super_class: dict(get_type_hints(super_class)))
+    def _get_annotations(self, include_extras: bool = False) -> dict[str, Any]:
+        """
+        Returns a dictionary mapping variable names to their type annotations.
+        Keep Annotations and other extras if include_extras is True.
+        """
+        return self._get_from_self_and_super(
+            extract_func=lambda super_class: dict(get_type_hints(super_class, include_extras=include_extras))
+        )
 
-    def _get_class_variables(self) -> dict:
+    def _get_class_variables(self, exclude_tap_ignores: bool = True) -> dict:
         """Returns a dictionary mapping class variables names to their additional information."""
         class_variable_names = {**self._get_annotations(), **self._get_class_dict()}.keys()
 
@@ -560,7 +595,13 @@ def _get_class_variables(self) -> dict:
             class_variables = {}
             for variable in class_variable_names:
                 class_variables[variable] = {"comment": ""}
-
+        if exclude_tap_ignores:
+            extra_annotations = self._get_annotations(include_extras=True)
+            return {
+                var: data
+                for var, data in class_variables.items()
+                if not self._is_ignored_argument(var, extra_annotations)
+            }
         return class_variables
 
     def _get_argument_names(self) -> set[str]:

src/tap/utils.py

@@ -1,28 +1,33 @@
-from argparse import ArgumentParser, ArgumentTypeError
 import ast
-from base64 import b64encode, b64decode
 import inspect
-from io import StringIO
-from json import JSONEncoder
 import os
 import pickle
 import re
 import subprocess
+import sys
 import textwrap
 import tokenize
+import warnings
+from argparse import ArgumentParser, ArgumentTypeError
+from base64 import b64decode, b64encode
+from io import StringIO
+from json import JSONEncoder
 from types import UnionType
 from typing import (
+    Annotated,
     Any,
     Callable,
     Generator,
     Iterable,
     Iterator,
     Literal,
     Optional,
+    TypeAlias,
+    TypeVar,
 )
-from typing_inspect import get_args as typing_inspect_get_args, get_origin as typing_inspect_get_origin
-import warnings
 
+from typing_inspect import get_args as typing_inspect_get_args
+from typing_inspect import get_origin as typing_inspect_get_origin
 
 NO_CHANGES_STATUS = """nothing to commit, working tree clean"""
 PRIMITIVES = (str, int, float, bool)
@@ -594,3 +599,26 @@ def get_args(tp: Any) -> tuple[type, ...]:
         return tp.__args__
 
     return typing_inspect_get_args(tp)
+
+
+_T = TypeVar("_T")
+
+
+class _TapIgnoreMarker:
+    """Internal marker that if present in a type annotation indicates that the argument should be ignored."""
+
+
+# TODO: Python 3.12 turn this into a TypeAliasType for better IDE tooltips
+TapIgnore: TypeAlias = Annotated[_T, _TapIgnoreMarker]
+"""
+Type annotation to indicate that an argument should be ignored by Tap and not be added as an argument.
+
+Usage:
+    from tap import Tap, TapIgnore
+
+    class Args(Tap):
+        a: int
+
+        # TapIgnore is generic and preserves the type of the ignored attribute
+        e: TapIgnore[int] = 5
+"""