Add defaultdict and Any to PYTHON_TYPE_IMPORTS (#2860)

* Add defaultdict and Any to PYTHON_TYPE_IMPORTS

* Expand PYTHON_TYPE_IMPORTS and add dynamic fallback

* Use try-except with noqa instead of suppress

* Use suppress for ImportError handling

* Add test for dynamic type import resolution

Author: koxudaxi

docs/python-model.md

@@ -200,6 +200,66 @@ datamodel-codegen --input-model ./mymodule.py:OPENAPI_SPEC --input-file-type ope
 
 ---
 
+## Custom Python Types with x-python-type {#x-python-type}
+
+When using `x-python-type` in JSON Schema (via `WithJsonSchema` in Pydantic), the generator automatically resolves and generates the required imports.
+
+### Automatic Import Resolution {#import-resolution}
+
+The generator supports many common Python types out of the box:
+
+| Module | Supported Types |
+|--------|-----------------|
+| `typing` | `Any`, `Union`, `Optional`, `Literal`, `Final`, `ClassVar`, `Annotated`, `TypeVar`, `TypeAlias`, `Never`, `NoReturn`, `Self`, `LiteralString`, `TypeGuard`, `Type` |
+| `collections` | `defaultdict`, `OrderedDict`, `Counter`, `deque`, `ChainMap` |
+| `collections.abc` | `Callable`, `Iterable`, `Iterator`, `Generator`, `Awaitable`, `Coroutine`, `AsyncIterable`, `AsyncIterator`, `AsyncGenerator`, `Mapping`, `MutableMapping`, `Sequence`, `MutableSequence`, `Set`, `MutableSet`, `Collection`, `Reversible` |
+| `pathlib` | `Path`, `PurePath` |
+| `decimal` | `Decimal` |
+| `uuid` | `UUID` |
+| `datetime` | `datetime`, `date`, `time`, `timedelta` |
+| `enum` | `Enum`, `IntEnum`, `StrEnum`, `Flag`, `IntFlag` |
+| `re` | `Pattern`, `Match` |
+
+For types not in this list, the generator dynamically searches common modules to resolve imports.
+
+### Example {#x-python-type-example}
+
+**mymodule.py**
+```python
+from collections import defaultdict
+from typing import Any, Annotated
+from pydantic import BaseModel, Field, WithJsonSchema
+
+class Config(BaseModel):
+    data: Annotated[
+        defaultdict[str, Annotated[dict[str, Any], Field(default_factory=dict)]],
+        WithJsonSchema({'type': 'object', 'x-python-type': 'defaultdict[str, dict[str, Any]]'})
+    ] | None = None
+```
+
+```bash
+datamodel-codegen --input-model ./mymodule.py:Config --output-model-type typing.TypedDict
+```
+
+**✨ Generated output**
+```python
+from __future__ import annotations
+
+from collections import defaultdict
+from typing import Any, TypedDict
+
+from typing_extensions import NotRequired
+
+
+class Config(TypedDict):
+    data: NotRequired[defaultdict[str, dict[str, Any]] | None]
+```
+
+!!! tip "Fully Qualified Paths"
+    You can also use fully qualified paths in `x-python-type` (e.g., `collections.defaultdict`), which are always resolved correctly regardless of the static mapping.
+
+---
+
 ## Mutual Exclusion {#mutual-exclusion}
 
 `--input-model` cannot be used with:

src/datamodel_code_generator/parser/jsonschema.py

@@ -7,6 +7,7 @@
 from __future__ import annotations
 
 import enum as _enum
+import importlib
 import json
 import re
 from collections import defaultdict
@@ -561,6 +562,7 @@ class JsonSchemaParser(Parser):
     }
 
     PYTHON_TYPE_IMPORTS: ClassVar[dict[str, Import]] = {
+        # collections.abc
         "Callable": Import.from_full_path("collections.abc.Callable"),
         "Iterable": Import.from_full_path("collections.abc.Iterable"),
         "Iterator": Import.from_full_path("collections.abc.Iterator"),
@@ -570,9 +572,57 @@ class JsonSchemaParser(Parser):
         "AsyncIterable": Import.from_full_path("collections.abc.AsyncIterable"),
         "AsyncIterator": Import.from_full_path("collections.abc.AsyncIterator"),
         "AsyncGenerator": Import.from_full_path("collections.abc.AsyncGenerator"),
+        "Mapping": Import.from_full_path("collections.abc.Mapping"),
+        "MutableMapping": Import.from_full_path("collections.abc.MutableMapping"),
+        "Sequence": Import.from_full_path("collections.abc.Sequence"),
+        "MutableSequence": Import.from_full_path("collections.abc.MutableSequence"),
+        "Set": Import.from_full_path("collections.abc.Set"),
+        "MutableSet": Import.from_full_path("collections.abc.MutableSet"),
+        "Collection": Import.from_full_path("collections.abc.Collection"),
+        "Reversible": Import.from_full_path("collections.abc.Reversible"),
+        # collections
+        "defaultdict": Import.from_full_path("collections.defaultdict"),
+        "OrderedDict": Import.from_full_path("collections.OrderedDict"),
+        "Counter": Import.from_full_path("collections.Counter"),
+        "deque": Import.from_full_path("collections.deque"),
+        "ChainMap": Import.from_full_path("collections.ChainMap"),
+        # re
         "Pattern": Import.from_full_path("re.Pattern"),
         "Match": Import.from_full_path("re.Match"),
+        # typing
+        "Any": Import.from_full_path("typing.Any"),
         "Type": Import.from_full_path("typing.Type"),
+        "Union": Import.from_full_path("typing.Union"),
+        "Optional": Import.from_full_path("typing.Optional"),
+        "Literal": Import.from_full_path("typing.Literal"),
+        "Final": Import.from_full_path("typing.Final"),
+        "ClassVar": Import.from_full_path("typing.ClassVar"),
+        "Annotated": Import.from_full_path("typing.Annotated"),
+        "TypeVar": Import.from_full_path("typing.TypeVar"),
+        "TypeAlias": Import.from_full_path("typing.TypeAlias"),
+        "Never": Import.from_full_path("typing.Never"),
+        "NoReturn": Import.from_full_path("typing.NoReturn"),
+        "Self": Import.from_full_path("typing.Self"),
+        "LiteralString": Import.from_full_path("typing.LiteralString"),
+        "TypeGuard": Import.from_full_path("typing.TypeGuard"),
+        # pathlib
+        "Path": Import.from_full_path("pathlib.Path"),
+        "PurePath": Import.from_full_path("pathlib.PurePath"),
+        # decimal
+        "Decimal": Import.from_full_path("decimal.Decimal"),
+        # uuid
+        "UUID": Import.from_full_path("uuid.UUID"),
+        # datetime
+        "datetime": Import.from_full_path("datetime.datetime"),
+        "date": Import.from_full_path("datetime.date"),
+        "time": Import.from_full_path("datetime.time"),
+        "timedelta": Import.from_full_path("datetime.timedelta"),
+        # enum
+        "Enum": Import.from_full_path("enum.Enum"),
+        "IntEnum": Import.from_full_path("enum.IntEnum"),
+        "StrEnum": Import.from_full_path("enum.StrEnum"),
+        "Flag": Import.from_full_path("enum.Flag"),
+        "IntFlag": Import.from_full_path("enum.IntFlag"),
     }
 
     # Types that require x-python-type override regardless of schema type
@@ -1355,6 +1405,34 @@ def _extract_all_type_names(self, type_str: str) -> list[str]:  # noqa: PLR6301
         pattern = r"(?<![.\w])([A-Z]\w*)"
         return re.findall(pattern, type_str)
 
+    @staticmethod
+    @lru_cache(maxsize=256)
+    def _resolve_type_import_dynamic(type_name: str) -> Import | None:
+        """Dynamically resolve import for a type name from known modules."""
+        modules_to_check = (
+            "typing",
+            "collections.abc",
+            "collections",
+            "pathlib",
+            "decimal",
+            "uuid",
+            "datetime",
+            "enum",
+            "re",
+        )
+        for module_name in modules_to_check:
+            with suppress(ImportError):
+                module = importlib.import_module(module_name)
+                if hasattr(module, type_name):
+                    return Import.from_full_path(f"{module_name}.{type_name}")
+        return None
+
+    def _resolve_type_import(self, type_name: str) -> Import | None:
+        """Resolve import for a type name, with dynamic fallback."""
+        if type_name in self.PYTHON_TYPE_IMPORTS:
+            return self.PYTHON_TYPE_IMPORTS[type_name]
+        return self._resolve_type_import_dynamic(type_name)
+
     def _get_python_type_override(self, obj: JsonSchemaObject) -> DataType | None:
         """Get DataType from x-python-type if it's incompatible with schema type."""
         x_python_type = obj.extras.get("x-python-type")
@@ -1366,7 +1444,7 @@ def _get_python_type_override(self, obj: JsonSchemaObject) -> DataType | None:
             return None
 
         base_type = self._get_python_type_base(x_python_type)
-        import_ = self.PYTHON_TYPE_IMPORTS.get(base_type)
+        import_ = self._resolve_type_import(base_type)
 
         # Convert fully qualified path to short name when import is added
         type_str = x_python_type
@@ -1389,7 +1467,7 @@ def _get_python_type_override(self, obj: JsonSchemaObject) -> DataType | None:
         # Collect imports for all nested types (e.g., Iterable inside Callable[[Iterable[str]], str])
         for type_name in self._extract_all_type_names(type_str):
             if type_name != base_type:
-                nested_import = self.PYTHON_TYPE_IMPORTS.get(type_name)
+                nested_import = self._resolve_type_import(type_name)
                 if nested_import:
                     nested_imports.append(self.data_type(import_=nested_import))
 

tests/data/expected/main/jsonschema/x_python_type_dynamic_resolve.py

@@ -0,0 +1,13 @@
+# generated by datamodel-codegen:
+#   filename:  x_python_type_dynamic_resolve.json
+#   timestamp: 2019-07-26T00:00:00+00:00
+
+from __future__ import annotations
+
+from typing import NamedTuple, TypedDict
+
+from typing_extensions import NotRequired
+
+
+class Model(TypedDict):
+    point: NotRequired[NamedTuple]

tests/data/jsonschema/x_python_type_dynamic_resolve.json

@@ -0,0 +1,9 @@
+{
+  "type": "object",
+  "properties": {
+    "point": {
+      "type": "string",
+      "x-python-type": "NamedTuple"
+    }
+  }
+}

tests/main/jsonschema/test_main_jsonschema.py

@@ -7162,3 +7162,14 @@ def test_x_python_type_nested_unknown_type(output_file: Path) -> None:
         assert_func=assert_file_content,
         extra_args=["--output-model-type", "typing.TypedDict"],
     )
+
+
+def test_x_python_type_dynamic_resolve(output_file: Path) -> None:
+    """Test x-python-type with types resolved dynamically (not in static PYTHON_TYPE_IMPORTS)."""
+    run_main_and_assert(
+        input_path=JSON_SCHEMA_DATA_PATH / "x_python_type_dynamic_resolve.json",
+        output_path=output_file,
+        input_file_type=None,
+        assert_func=assert_file_content,
+        extra_args=["--output-model-type", "typing.TypedDict"],
+    )