diff --git a/.github/workflows/pythonpackage.yml b/.github/workflows/pythonpackage.yml
index 117141b..c2e78c0 100644
--- a/.github/workflows/pythonpackage.yml
+++ b/.github/workflows/pythonpackage.yml
@@ -44,16 +44,15 @@ jobs:
 
             -   name: Install dependencies
                 shell: bash
-                env:
-                    SPECIAL: ${{ matrix.special }}
                 run: |
-                    if [[ $SPECIAL == '; no-optional' ]]; then
-                        pip install -e .[test_no_optional]
-                    elif [[ $SPECIAL == '; pre-release' ]]; then
-                        pip install --pre -e .[test] --upgrade --force-reinstall
-                    else
-                        pip install -e .[test]
-                    fi
+                    case "${{ matrix.special }}" in
+                        "; no-optional")
+                            pip install -e .[test_no_optional] ;;
+                        "; pre-release")
+                            pip install --pre -e .[test] --upgrade --force-reinstall ;;
+                        *)
+                            pip install -e .[test] ;;
+                    esac
 
             -   name: Python info
                 run: |
@@ -65,14 +64,13 @@ jobs:
 
             -   name: Test with pytest
                 shell: bash
-                env:
-                    SPECIAL: ${{ matrix.special }}
                 run: |
-                    if [[ $SPECIAL == '; no-optional' ]]; then
-                        pytest --mypy
-                    else
-                        pytest --mypy --doctest-modules
-                    fi
+                    case "${{ matrix.special }}" in
+                        "; no-optional")
+                            pytest --mypy ;;
+                        *)
+                            pytest --mypy --doctest-modules ;;
+                    esac
 
             -   name: Run codecov
                 uses: codecov/codecov-action@v2
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index cd62be9..6cb3858 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -6,6 +6,14 @@ All notable changes to this project will be documented in this file.
 This project adheres to `Semantic Versioning <http://semver.org/>`_.
 
 
+2.3.0
+*****
+* Added ``UserMapping`` entry points for the IPython key completioner
+  and pretty printer.
+* Added a decorator for applying the effect of ``warnings.filterwarnings``
+  to the decorated function.
+
+
 2.2.0
 *****
 * Added a decorator for constructing positional-only signatures.
diff --git a/README.rst b/README.rst
index 1a8bdfc..f34daa6 100644
--- a/README.rst
+++ b/README.rst
@@ -22,7 +22,7 @@
 
 
 ################
-Nano-Utils 2.2.0
+Nano-Utils 2.3.0
 ################
 Utility functions used throughout the various nlesc-nano repositories.
 
diff --git a/nanoutils/__version__.py b/nanoutils/__version__.py
index b66927e..fff80ed 100644
--- a/nanoutils/__version__.py
+++ b/nanoutils/__version__.py
@@ -1,3 +1,3 @@
 """The **Nano-Utils** version."""
 
-__version__ = '2.2.0'
+__version__ = '2.3.0'
diff --git a/nanoutils/_user_dict.py b/nanoutils/_user_dict.py
index 4f8b35a..85141dc 100644
--- a/nanoutils/_user_dict.py
+++ b/nanoutils/_user_dict.py
@@ -26,6 +26,12 @@
 from .utils import positional_only
 from .typing_utils import Protocol, runtime_checkable
 
+if TYPE_CHECKING:
+    from IPython.lib.pretty import RepresentationPrinter
+
+    class _ReprFunc(Protocol[_KT, _VT]):
+        def __call__(self, __dct: dict[_KT, _VT], *, width: int) -> str: ...
+
 __all__ = ["UserMapping", "MutableUserMapping", "_DictLike", "_SupportsKeysAndGetItem"]
 
 _SENTINEL = object()
@@ -62,6 +68,17 @@ def __getitem__(self, __key: _KT) -> _VT_co:
 ]
 
 
+def _repr_func(self: UserMapping[_KT, _VT], func: _ReprFunc[_KT, _VT]) -> str:
+    """Helper function for :meth:`UserMapping.__repr__`."""
+    cls = type(self)
+    dict_repr = func(self._dict, width=76)
+    if len(dict_repr) <= 76:
+        return f"{cls.__name__}({dict_repr})"
+    else:
+        dict_repr2 = textwrap.indent(dict_repr[1:-1], 3 * " ")
+        return f"{cls.__name__}({{\n {dict_repr2},\n}})"
+
+
 class UserMapping(Mapping[_KT, _VT_co]):
     """Base class for user-defined immutable mappings."""
 
@@ -104,14 +121,21 @@ def copy(self: _ST1) -> _ST1:
     @reprlib.recursive_repr(fillvalue='...')
     def __repr__(self) -> str:
         """Implement :func:`repr(self) <repr>`."""
-        cls = type(self)
-        width = 80 - 2 - len(cls.__name__)
-        dct_repr = pformat(self._dict, width=width)
-        if len(dct_repr) <= width:
-            return f"{cls.__name__}({dct_repr})"
-        else:
-            dct_repr2 = textwrap.indent(dct_repr[1:-1], 3 * " ")
-            return f"{cls.__name__}({{\n {dct_repr2},\n}})"
+        return _repr_func(self, func=pformat)
+
+    def _repr_pretty_(self, p: RepresentationPrinter, cycle: bool) -> None:
+        """Entry point for the :mod:`IPython <IPython.lib.pretty>` pretty printer."""
+        if cycle:
+            p.text(f"{type(self).__name__}(...)")
+            return None
+
+        from IPython.lib.pretty import pretty
+        string = _repr_func(self, func=lambda dct, width: pretty(dct, max_width=width))
+        p.text(string)
+
+    def _ipython_key_completions_(self) -> KeysView[_KT]:
+        """Entry point for the IPython key completioner."""
+        return self.keys()
 
     def __hash__(self) -> int:
         """Implement :func:`hash(self) <hash>`.
diff --git a/nanoutils/utils.py b/nanoutils/utils.py
index e035463..7e412e5 100644
--- a/nanoutils/utils.py
+++ b/nanoutils/utils.py
@@ -18,6 +18,7 @@
 import warnings
 import importlib
 import inspect
+import functools
 from types import ModuleType
 from functools import wraps
 from typing import (
@@ -34,9 +35,10 @@
     MutableMapping,
     Collection,
     cast,
-    overload
+    overload,
 )
 
+from .typing_utils import Literal
 from .empty import EMPTY_CONTAINER
 
 __all__ = [
@@ -58,6 +60,7 @@
     'positional_only',
     'UserMapping',
     'MutableUserMapping',
+    'warning_filter',
 ]
 
 _T = TypeVar('_T')
@@ -737,6 +740,75 @@ def positional_only(func: _FT) -> _FT:
     return func
 
 
+def warning_filter(
+    action: Literal["default", "error", "ignore", "always", "module", "once"],
+    message: str = "",
+    category: type[Warning] = Warning,
+    module: str = "",
+    lineno: int = 0,
+    append: bool = False,
+) -> Callable[[_FT], _FT]:
+    """A decorator for wrapping function calls with :func:`warnings.filterwarnings`.
+
+    Examples
+    --------
+    .. code-block:: python
+
+        >>> from nanoutils import warning_filter
+        >>> import warnings
+
+        >>> @warning_filter("error", category=UserWarning)
+        ... def func():
+        ...     warnings.warn("test", UserWarning)
+
+        >>> func()
+        Traceback (most recent call last):
+            ...
+        UserWarning: test
+
+    Parameters
+    ----------
+    action : :class:`str`
+        One of the following strings:
+
+        * ``"default"``: Print the first occurrence of matching warnings for each location (module + line number) where the warning is issued
+        * ``"error"``: Turn matching warnings into exceptions
+        * ``"ignore"``: Never print matching warnings
+        * ``"always"``: Always print matching warnings
+        * ``"module"``: Print the first occurrence of matching warnings for each module where the warning is issued (regardless of line number)
+        * ``"once"``: Print only the first occurrence of matching warnings, regardless of location
+
+    message : :class:`str`, optional
+        A string containing a regular expression that the start of the warning message must match.
+        The expression is compiled to always be case-insensitive.
+    category : :class:`type[Warning] <type>`
+        The to-be affected :class:`Warning` (sub-)class.
+    module : :class:`str`, optional
+        A string containing a regular expression that the module name must match.
+        The expression is compiled to be case-sensitive.
+    lineno : :class:`int`
+        An integer that the line number where the warning occurred must match,
+        or 0 to match all line numbers.
+    append : :class:`bool`
+        Whether the warning entry is inserted at the end.
+
+    See Also
+    --------
+    :func:`warnings.filterwarnings` :
+        Insert a simple entry into the list of warnings filters (at the front).
+
+    """
+    def decorator(func: _FT) -> _FT:
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            with warnings.catch_warnings():
+                warnings.filterwarnings(action, message, category, module, lineno, append)
+                ret = func(*args, **kwargs)
+            return ret
+        return cast(_FT, wrapper)
+    return decorator
+
+
 # Move to the end to reduce the risk of circular imports
 from ._partial import PartialPrepend
 from ._set_attr import SetAttr
@@ -747,5 +819,5 @@ def positional_only(func: _FT) -> _FT:
 
 __doc__ = construct_api_doc(
     globals(),
-    decorators={'set_docstring', 'raise_if', 'ignore_if', 'positional_only'},
+    decorators={'set_docstring', 'raise_if', 'ignore_if', 'positional_only', 'warning_filter'},
 )
diff --git a/setup.py b/setup.py
index ebaa4c2..11c26f2 100644
--- a/setup.py
+++ b/setup.py
@@ -42,6 +42,7 @@
     'pyyaml',
     'h5py',
     'numpy',
+    'ipython',
 ]
 tests_require += docs_require
 tests_require += build_requires
diff --git a/tests/test_dtype_mapping.py b/tests/test_dtype_mapping.py
index 7b1f39b..91f1978 100644
--- a/tests/test_dtype_mapping.py
+++ b/tests/test_dtype_mapping.py
@@ -3,7 +3,7 @@
 import sys
 import textwrap
 from typing import TYPE_CHECKING, no_type_check
-from collections.abc import Iterator
+from collections.abc import Iterator, Callable
 
 import pytest
 from assertionlib import assertion
@@ -18,6 +18,14 @@
     import numpy.typing as npt
     import _pytest
 
+try:
+    from IPython.lib.pretty import pretty
+except ModuleNotFoundError:
+    IPYTHON: bool = False
+    pretty = NotImplemented
+else:
+    IPYTHON = True
+
 
 class BasicMapping:
     def __init__(self, dct: dict[str, npt.DTypeLike]) -> None:
@@ -128,16 +136,21 @@ def test_repr(self, obj: DTypeMapping) -> None:
         )""").strip()
         assertion.str_eq(obj, string1, str_converter=repr)
 
-        string2 = textwrap.dedent(f"""
+        string2 = f"{type(obj).__name__}()"
+        assertion.str_eq(type(obj)(), string2, str_converter=repr)
+
+    @pytest.mark.parametrize("str_func", [
+        str,
+        pytest.param(pretty, marks=pytest.mark.skipif(not IPYTHON, reason="Requires IPython")),
+    ], ids=["str", "pretty"])
+    def test_str(self, obj: DTypeMapping, str_func: Callable[[object], str]) -> None:
+        string = textwrap.dedent(f"""
         {type(obj).__name__}(
             a = int64,
             b = float64,
             c = <U5,
         )""").strip()
-        assertion.str_eq(obj, string2, str_converter=str)
-
-        string3 = f"{type(obj).__name__}()"
-        assertion.str_eq(type(obj)(), string3, str_converter=repr)
+        assertion.str_eq(obj, string, str_converter=str_func)
 
     @pytest.mark.skipif(sys.version_info < (3, 9), reason="Requires python >= 3.9")
     @no_type_check
diff --git a/tests/test_user_mapping.py b/tests/test_user_mapping.py
index 4fc6b6b..654b5c5 100644
--- a/tests/test_user_mapping.py
+++ b/tests/test_user_mapping.py
@@ -7,7 +7,7 @@
 import textwrap
 import string
 from typing import TYPE_CHECKING, no_type_check
-from collections.abc import KeysView, ValuesView, ItemsView, Iterator
+from collections.abc import KeysView, ValuesView, ItemsView, Iterator, Callable
 
 import pytest
 from assertionlib import assertion
@@ -17,6 +17,14 @@
 if TYPE_CHECKING:
     import _pytest
 
+try:
+    from IPython.lib.pretty import pretty
+except ModuleNotFoundError:
+    IPYTHON: bool = False
+    pretty = NotImplemented
+else:
+    IPYTHON = True
+
 
 class BasicMapping:
     def __init__(self, dct: dict[str, int]) -> None:
@@ -75,9 +83,14 @@ def test_eq(self, obj: UserMapping[str, int]) -> None:
     def test_getitem(self, obj: UserMapping[str, int], key: str, value: int) -> None:
         assertion.eq(obj[key], value)
 
-    def test_repr(self, obj: UserMapping[str, int]) -> None:
+    @pytest.mark.parametrize("str_func", [
+        str,
+        repr,
+        pytest.param(pretty, marks=pytest.mark.skipif(not IPYTHON, reason="Requires IPython")),
+    ], ids=["str", "repr", "pretty"])
+    def test_repr(self, obj: UserMapping[str, int], str_func: Callable[[object], str]) -> None:
         string1 = f"{type(obj).__name__}({{'a': 0, 'b': 1, 'c': 2}})"
-        assertion.str_eq(obj, string1)
+        assertion.str_eq(obj, string1, str_converter=str_func)
 
         cls = type(obj)
         ref2 = cls(zip(string.ascii_lowercase[:12], range(12)))
@@ -97,7 +110,12 @@ def test_repr(self, obj: UserMapping[str, int]) -> None:
             'l': 11,
         }})
         """).strip()
-        assertion.str_eq(ref2, string2)
+        assertion.str_eq(ref2, string2, str_converter=str_func)
+
+    @pytest.mark.skipif(not IPYTHON, reason="Rquires IPython")
+    def test_pretty_repr(self, obj: UserMapping[str, int]) -> None:
+        string1 = f"{type(obj).__name__}({{'a': 0, 'b': 1, 'c': 2}})"
+        assertion.str_eq(obj, string1, str_converter=pretty)
 
     def test_hash(self, obj: UserMapping[str, int]) -> None:
         if isinstance(obj, MutableUserMapping):
@@ -134,6 +152,10 @@ def test_fromkeys(self, obj: UserMapping[str, int]) -> None:
         assertion.isinstance(dct, cls)
         assertion.eq(dct.keys(), obj.keys())
 
+    def test_key_completions(self, obj: UserMapping[str, int]) -> None:
+        assertion.isinstance(obj._ipython_key_completions_(), KeysView)
+        assertion.eq(obj._ipython_key_completions_(), obj.keys())
+
     def test_get(self, obj: UserMapping[str, int]) -> None:
         assertion.eq(obj.get("a"), 0)
         assertion.is_(obj.get("d"), None)