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Merged
jbjd merged 3 commits into from
Jan 17, 2026
Merged

Improvement: Simply NamedTuple with defaults #49

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9976292
Convert namedtuple after visit
jbjd Jan 16, 2026
7ce60ee
Improvement: Simply NamedTuple with defaults
jbjd Jan 17, 2026
106c0c2
Merge
jbjd Jan 17, 2026
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59 changes: 42 additions & 17 deletions personal_python_ast_optimizer/parser/skipper.py
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Original file line number Diff line number Diff line change
Expand Up @@ -195,25 +195,16 @@ def visit_ClassDef(self, node: ast.ClassDef) -> ast.AST | None:
skip_base_classes(node, self.tokens_config.classes_to_skip)
skip_decorators(node, self.tokens_config.decorators_to_skip)

parsed_node = self.generic_visit(node)

if (
self.token_types_config.simplify_named_tuples
and isinstance(parsed_node, ast.ClassDef)
and self._is_simple_named_tuple(parsed_node)
and isinstance(node, ast.ClassDef)
and self._is_simple_named_tuple(node)
):
self._simplified_named_tuple = True
named_tuple = ast.Call(
ast.Name("namedtuple"),
[
ast.Constant(parsed_node.name),
ast.List([ast.Constant(n.target.id) for n in parsed_node.body]), # type: ignore
],
[],
)
return ast.Assign([ast.Name(parsed_node.name)], named_tuple)
named_tuple = self._build_named_tuple(node)
return ast.Assign([ast.Name(node.name)], named_tuple)

return parsed_node
return self.generic_visit(node)

@staticmethod
def _is_simple_named_tuple(node: ast.ClassDef) -> bool:
Expand All @@ -224,13 +215,47 @@ def _is_simple_named_tuple(node: ast.ClassDef) -> bool:
and not node.keywords
and not node.decorator_list
and all(
isinstance(n, ast.AnnAssign)
and isinstance(n.target, ast.Name)
and n.value is None
isinstance(n, ast.AnnAssign) and isinstance(n.target, ast.Name)
for n in node.body
)
)

@staticmethod
def _build_named_tuple(node: ast.ClassDef) -> ast.Call:
"""Build what a namedtuple node would be for a given
class def inheriting from NamedTuple with only AnnAssigns in the body."""

defaults: list[ast.expr]

if node.body:
defaults = [node.body[0].value] if node.body[0].value is not None else [] # type: ignore

for i in range(1, len(node.body)):
assign: ast.AnnAssign = node.body[i] # type: ignore
if assign.value is not None:
defaults.append(assign.value)
elif node.body[i - 1].value is not None: # type: ignore
raise ValueError(
f"Non-default namedtuple {node.name} field "
"cannot follow default field"
)

else:
defaults = []

keywords: list[ast.keyword] = (
[ast.keyword("defaults", ast.List(defaults))] if defaults else []
)

return ast.Call(
ast.Name("namedtuple"),
[
ast.Constant(node.name),
ast.List([ast.Constant(n.target.id) for n in node.body]), # type: ignore
],
keywords,
)

def visit_FunctionDef(self, node: ast.FunctionDef) -> ast.AST | None:
return self._handle_function_node(node)

Expand Down
2 changes: 1 addition & 1 deletion requirements_dev.txt
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Expand Up @@ -2,4 +2,4 @@ codespell==2.4.1
mypy==1.19.1
pytest==9.0.2
pytest-cov==7.0.0
ruff==0.14.11
ruff==0.14.12
31 changes: 31 additions & 0 deletions tests/parser/test_tuple.py
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Expand Up @@ -50,6 +50,17 @@ class A(NamedTuple):
""",
"from collections import OrderedDict,namedtuple\nA=namedtuple('A',['foo','bar'])\nb=OrderedDict()", # noqa: E501
),
(
"""
from typing import NamedTuple

class A(NamedTuple):
foo: int
bar: int = 2
spam: str = 'a'
""",
"from collections import namedtuple\nA=namedtuple('A',['foo','bar','spam'],defaults=[2,'a'])", # noqa: E501
),
]


Expand All @@ -61,3 +72,23 @@ def test_simplify_named_tuple(before: str, after: str):
before_and_after,
token_types_config=TokenTypesConfig(simplify_named_tuples=True),
)


def test_simplify_named_tuple_error():
before_and_after = BeforeAndAfter(
"""
from typing import NamedTuple

class A(NamedTuple):
foo: int = 2
bar: int
spam: str = 'a'
""",
"",
)

with pytest.raises(ValueError):
run_minifier_and_assert_correct(
before_and_after,
token_types_config=TokenTypesConfig(simplify_named_tuples=True),
)
2 changes: 1 addition & 1 deletion version.txt
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Original file line number Diff line number Diff line change
@@ -1 +1 @@
6.0.1
6.0.2