Add support for python 3.14

.github/workflows/tests.yaml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python: ["3.9", "3.10", "3.11", "3.12", "3.13"]
+        python: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14-dev"]
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
@@ -59,7 +59,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python: ["3.9", "3.10", "3.11", "3.12", "3.13"]
+        python: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14-dev"]
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
@@ -74,7 +74,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python: ["3.10", "3.12"]
+        python: ["3.10", "3.12", "3.14-dev"]
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
@@ -249,7 +249,7 @@ jobs:
             -Dsonar.exclusions=sphinx/**
             -Dsonar.tests=jsonargparse_tests
             -Dsonar.python.coverage.reportPaths=coverage_*.xml
-            -Dsonar.python.version=3.9,3.10,3.11,3.12,3.13
+            -Dsonar.python.version=3.9,3.10,3.11,3.12,3.13,3.14
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}  # Needed to get PR information, if any
           SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}

CHANGELOG.rst

@@ -15,6 +15,11 @@ paths are considered internals and can change in minor and patch releases.
 v4.41.0 (2025-08-??)
 --------------------
 
+Added
+^^^^^
+- Support for Python 3.14 (`#753
+  <https://github.com/omni-us/jsonargparse/pull/753>`__).
+
 Changed
 ^^^^^^^
 - Removed support for python 3.8 (`#752

jsonargparse/_typehints.py

@@ -1615,9 +1615,10 @@ def __init__(self, class_type: Type, lazy_kwargs: dict):
                 self.__dict__[name] = seen_methods[id(member)]
             else:
                 lazy_method = partial(self._lazy_init_then_call_method, name)
-                self.__dict__[name] = lazy_method
                 if name == "__call__":
+                    lazy_method = staticmethod(lazy_method)  # type: ignore[assignment]
                     self._lazy.__call__ = lazy_method  # type: ignore[method-assign]
+                self.__dict__[name] = lazy_method
                 seen_methods[id(member)] = lazy_method
 
     def _lazy_init(self):

jsonargparse_tests/conftest.py

@@ -192,6 +192,12 @@ def source_unavailable(obj=None):
         yield
 
 
+@pytest.fixture(autouse=True)
+def no_color():
+    with patch.dict(os.environ, {"NO_COLOR": "true"}):
+        yield
+
+
 def get_parser_help(parser: ArgumentParser, strip=False, columns=columns) -> str:
     out = StringIO()
     with patch.dict(os.environ, {"COLUMNS": columns}):

jsonargparse_tests/test_core.py

@@ -3,6 +3,7 @@
 import json
 import os
 import pickle
+import sys
 from calendar import Calendar
 from contextlib import redirect_stderr
 from io import StringIO
@@ -266,16 +267,17 @@ def test_default_env_override_false():
 
 
 def test_env_prefix_true():
-    parser = ArgumentParser(env_prefix=True, default_env=True, exit_on_error=False)
-    parser.add_argument("--test_arg", type=str, required=True)
+    with patch("sys.argv", ["fake.py"]), patch.dict(sys.modules, {"__main__": {}}):
+        parser = ArgumentParser(env_prefix=True, default_env=True, exit_on_error=False)
+        assert parser.prog == "fake.py"
+        parser.add_argument("--test_arg", type=str, required=True)
 
-    with patch.dict(os.environ, {"TEST_ARG": "one"}):
-        pytest.raises(ArgumentError, lambda: parser.parse_args([]))
+        with patch.dict(os.environ, {"TEST_ARG": "one"}):
+            pytest.raises(ArgumentError, lambda: parser.parse_args([]))
 
-    prefix = os.path.splitext(parser.prog)[0].upper()
-    with patch.dict(os.environ, {f"{prefix}_TEST_ARG": "one"}):
-        cfg = parser.parse_args([])
-    assert "one" == cfg.test_arg
+        with patch.dict(os.environ, {"FAKE_TEST_ARG": "one"}):
+            cfg = parser.parse_args([])
+        assert "one" == cfg.test_arg
 
 
 def test_env_prefix_false():

jsonargparse_tests/test_dataclass_like.py

@@ -2,6 +2,7 @@
 
 import dataclasses
 import json
+import sys
 from typing import Any, Dict, Generic, List, Literal, Optional, Tuple, TypeVar, Union
 from unittest.mock import patch
 
@@ -537,8 +538,12 @@ def test_generic_dataclass(parser):
     help_str = get_parser_help(parser).lower()
     assert "--data.g1 g1          (required, type: int)" in help_str
     assert "--data.g2 [item,...]  (required, type: tuple[int, int])" in help_str
-    assert "--data.g3 g3          (required, type: union[str, int])" in help_str
-    assert "--data.g4 g4          (required, type: dict[str, union[int, bool]])" in help_str
+    if sys.version_info < (3, 14):
+        assert "--data.g3 g3          (required, type: union[str, int])" in help_str
+        assert "--data.g4 g4          (required, type: dict[str, union[int, bool]])" in help_str
+    else:
+        assert "--data.g3 g3          (required, type: str | int)" in help_str
+        assert "--data.g4 g4          (required, type: dict[str, int | bool])" in help_str
 
 
 @dataclasses.dataclass
@@ -551,8 +556,12 @@ def test_nested_generic_dataclass(parser):
     help_str = get_parser_help(parser).lower()
     assert "--x.y.g1 g1          (required, type: float)" in help_str
     assert "--x.y.g2 [item,...]  (required, type: tuple[float, float])" in help_str
-    assert "--x.y.g3 g3          (required, type: union[str, float])" in help_str
-    assert "--x.y.g4 g4          (required, type: dict[str, union[float, bool]])" in help_str
+    if sys.version_info < (3, 14):
+        assert "--x.y.g3 g3          (required, type: union[str, float])" in help_str
+        assert "--x.y.g4 g4          (required, type: dict[str, union[float, bool]])" in help_str
+    else:
+        assert "--x.y.g3 g3          (required, type: str | float)" in help_str
+        assert "--x.y.g4 g4          (required, type: dict[str, float | bool])" in help_str
 
 
 V = TypeVar("V")

jsonargparse_tests/test_postponed_annotations.py

@@ -2,6 +2,7 @@
 
 import dataclasses
 import os
+import sys
 from typing import TYPE_CHECKING, Dict, List, Optional, Tuple, Type, Union
 
 import pytest
@@ -172,8 +173,12 @@ def function_type_checking_union(p1: Union[bool, TypeCheckingClass1, int], p2: U
 def test_get_types_type_checking_union():
     types = get_types(function_type_checking_union)
     assert list(types) == ["p1", "p2"]
-    assert str(types["p1"]) == f"typing.Union[bool, {__name__}.TypeCheckingClass1, int]"
-    assert str(types["p2"]) == f"typing.Union[float, {__name__}.TypeCheckingClass2]"
+    if sys.version_info < (3, 14):
+        assert str(types["p1"]) == f"typing.Union[bool, {__name__}.TypeCheckingClass1, int]"
+        assert str(types["p2"]) == f"typing.Union[float, {__name__}.TypeCheckingClass2]"
+    else:
+        assert str(types["p1"]) == f"bool | {__name__}.TypeCheckingClass1 | int"
+        assert str(types["p2"]) == f"float | {__name__}.TypeCheckingClass2"
 
 
 def function_type_checking_alias(p1: type_checking_alias, p2: "type_checking_alias"):
@@ -183,8 +188,12 @@ def function_type_checking_alias(p1: type_checking_alias, p2: "type_checking_ali
 def test_get_types_type_checking_alias():
     types = get_types(function_type_checking_alias)
     assert list(types) == ["p1", "p2"]
-    assert str(types["p1"]) == f"typing.Union[int, {__name__}.TypeCheckingClass2, typing.List[str]]"
-    assert str(types["p2"]) == f"typing.Union[int, {__name__}.TypeCheckingClass2, typing.List[str]]"
+    if sys.version_info < (3, 14):
+        assert str(types["p1"]) == f"typing.Union[int, {__name__}.TypeCheckingClass2, typing.List[str]]"
+        assert str(types["p2"]) == f"typing.Union[int, {__name__}.TypeCheckingClass2, typing.List[str]]"
+    else:
+        assert str(types["p1"]) == f"int | {__name__}.TypeCheckingClass2 | typing.List[str]"
+        assert str(types["p2"]) == f"int | {__name__}.TypeCheckingClass2 | typing.List[str]"
 
 
 def function_type_checking_optional_alias(p1: type_checking_alias | None, p2: Optional["type_checking_alias"]):
@@ -194,8 +203,12 @@ def function_type_checking_optional_alias(p1: type_checking_alias | None, p2: Op
 def test_get_types_type_checking_optional_alias():
     types = get_types(function_type_checking_optional_alias)
     assert list(types) == ["p1", "p2"]
-    assert str(types["p1"]) == f"typing.Union[int, {__name__}.TypeCheckingClass2, typing.List[str], NoneType]"
-    assert str(types["p2"]) == f"typing.Union[int, {__name__}.TypeCheckingClass2, typing.List[str], NoneType]"
+    if sys.version_info < (3, 14):
+        assert str(types["p1"]) == f"typing.Union[int, {__name__}.TypeCheckingClass2, typing.List[str], NoneType]"
+        assert str(types["p2"]) == f"typing.Union[int, {__name__}.TypeCheckingClass2, typing.List[str], NoneType]"
+    else:
+        assert str(types["p1"]) == f"int | {__name__}.TypeCheckingClass2 | typing.List[str] | None"
+        assert str(types["p2"]) == f"int | {__name__}.TypeCheckingClass2 | typing.List[str] | None"
 
 
 def function_type_checking_list(p1: List[Union["TypeCheckingClass1", TypeCheckingClass2]]):
@@ -206,7 +219,10 @@ def test_get_types_type_checking_list():
     types = get_types(function_type_checking_list)
     assert list(types) == ["p1"]
     lst = "typing.List"
-    assert str(types["p1"]) == f"{lst}[typing.Union[{__name__}.TypeCheckingClass1, {__name__}.TypeCheckingClass2]]"
+    if sys.version_info < (3, 14):
+        assert str(types["p1"]) == f"{lst}[typing.Union[{__name__}.TypeCheckingClass1, {__name__}.TypeCheckingClass2]]"
+    else:
+        assert str(types["p1"]) == f"{lst}[{__name__}.TypeCheckingClass1 | {__name__}.TypeCheckingClass2]"
 
 
 def function_type_checking_tuple(p1: Tuple[TypeCheckingClass1, "TypeCheckingClass2"]):
@@ -239,7 +255,13 @@ def test_get_types_type_checking_dict():
     types = get_types(function_type_checking_dict)
     assert list(types) == ["p1"]
     dct = "typing.Dict"
-    assert str(types["p1"]) == f"{dct}[str, typing.Union[{__name__}.TypeCheckingClass1, {__name__}.TypeCheckingClass2]]"
+    if sys.version_info < (3, 14):
+        assert (
+            str(types["p1"])
+            == f"{dct}[str, typing.Union[{__name__}.TypeCheckingClass1, {__name__}.TypeCheckingClass2]]"
+        )
+    else:
+        assert str(types["p1"]) == f"{dct}[str, {__name__}.TypeCheckingClass1 | {__name__}.TypeCheckingClass2]"
 
 
 def function_type_checking_undefined_forward_ref(p1: List["Undefined"], p2: bool):  # type: ignore  # noqa: F821

jsonargparse_tests/test_signatures.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import json
+import sys
 from pathlib import Path
 from typing import Any, Dict, Generic, List, Optional, Tuple, TypeVar, Union
 from unittest.mock import patch
@@ -308,10 +309,17 @@ def test_add_class_conditional_kwargs(parser):
         expected += [
             "help for func (required, type: str)",
             "help for kmg1 (type: int, default: 1)",
-            "help for kmg2 (type: Union[str, float], default: Conditional<ast-resolver> {-, 2.3})",
             "help for kmg3 (type: bool, default: Conditional<ast-resolver> {True, False})",
             "help for kmg4 (type: int, default: Conditional<ast-resolver> {4, NOT_ACCEPTED})",
         ]
+        if sys.version_info < (3, 14):
+            expected += [
+                "help for kmg2 (type: Union[str, float], default: Conditional<ast-resolver> {-, 2.3})",
+            ]
+        else:
+            expected += [
+                "help for kmg2 (type: str | float, default: Conditional<ast-resolver> {-, 2.3})",
+            ]
     for value in expected:
         assert value in help_str
 

jsonargparse_tests/test_stubs_resolver.py

@@ -165,12 +165,16 @@ def test_get_params_classmethod():
         "debug",
         "errorlevel",
     ]
-    if sys.version_info >= (3, 12):
+    if sys.version_info >= (3, 14):
+        expected = expected[:4] + ["compresslevel", "preset"] + expected[4:]
+    elif sys.version_info >= (3, 12):
         expected = expected[:4] + ["compresslevel"] + expected[4:]
     assert expected == get_param_names(params)[: len(expected)]
     if sys.version_info >= (3, 10):
         assert all(
-            p.annotation is not inspect._empty for p in params if p.name not in {"fileobj", "compresslevel", "stream"}
+            p.annotation is not inspect._empty
+            for p in params
+            if p.name not in {"fileobj", "compresslevel", "stream", "preset"}
         )
     with mock_stubs_missing_types():
         params = get_params(TarFile, "open")

jsonargparse_tests/test_typehints.py

@@ -345,7 +345,10 @@ def test_tuple_union(parser, tmp_cwd):
     pytest.raises(ArgumentError, lambda: parser.parse_args(['--tuple=[2, "a"]']))
     pytest.raises(ArgumentError, lambda: parser.parse_args(['--tuple={"a":1, "b":"2"}']))
     help_str = get_parser_help(parser, strip=True)
-    assert "--tuple [ITEM,...] (type: Tuple[Union[int, EnumABC], Path_fc, NotEmptyStr], default: null)" in help_str
+    if sys.version_info < (3, 14):
+        assert "--tuple [ITEM,...] (type: Tuple[Union[int, EnumABC], Path_fc, NotEmptyStr], default: null)" in help_str
+    else:
+        assert "--tuple [ITEM,...] (type: Tuple[int | EnumABC, Path_fc, NotEmptyStr], default: null)" in help_str
 
 
 # list tests
@@ -1404,6 +1407,8 @@ def test_lazy_instance_callable():
     optimizer = lazy_optimizer([1, 2])
     assert optimizer.lr == 0.2
     assert optimizer.params == [1, 2]
+    optimizer = lazy_optimizer([3, 4])
+    assert optimizer.params == [3, 4]
 
 
 # other tests

pyproject.toml

@@ -25,6 +25,7 @@ classifiers = [
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: 3.14",
     "Intended Audience :: Developers",
     "Operating System :: POSIX :: Linux",
     "Operating System :: MacOS",
@@ -93,7 +94,7 @@ test = [
     "types-PyYAML>=6.0.11",
     "types-requests>=2.28.9",
     "responses>=0.12.0",
-    "pydantic>=2.3.0",
+    "pydantic>=2.3.0; python_version < '3.14'",  # restricted until pydantic installs correctly in 3.14
     "attrs>=22.2.0",
 ]
 test-no-urls = [
@@ -189,7 +190,7 @@ Villegas = "Villegas"
 [tool.tox]
 legacy_tox_ini = """
 [tox]
-envlist = py{39,310,311,312,313}-{all,no}-extras,omegaconf,pydantic-v1,without-pyyaml,without-future-annotations
+envlist = py{39,310,311,312,313,314}-{all,no}-extras,omegaconf,pydantic-v1,without-pyyaml,without-future-annotations
 skip_missing_interpreters = true
 
 [testenv]