Implement lazy imports for numpy and sqlalchemy to improve startup time

Author: yukinarit

serde/compat.py

@@ -22,7 +22,14 @@
 import typing_inspect
 from typing_extensions import TypeGuard, ParamSpec, TypeAliasType
 
-from .sqlalchemy import is_sqlalchemy_inspectable
+# Lazy SQLAlchemy imports to improve startup time
+
+
+# Lazy SQLAlchemy import wrapper to improve startup time
+def _is_sqlalchemy_inspectable(subject: Any) -> bool:
+    from .sqlalchemy import is_sqlalchemy_inspectable
+
+    return is_sqlalchemy_inspectable(subject)
 
 
 def get_np_origin(tp: type[Any]) -> Optional[Any]:
@@ -294,7 +301,7 @@ def dataclass_fields(cls: type[Any]) -> Iterator[dataclasses.Field]:  # type: ig
         real_type = resolved_hints.get(f.name)
         if real_type is not None:
             f.type = real_type
-            if is_generic(real_type) and is_sqlalchemy_inspectable(cls):
+            if is_generic(real_type) and _is_sqlalchemy_inspectable(cls):
                 f.type = get_args(real_type)[0]
 
     return iter(raw_fields)

serde/core.py

@@ -11,6 +11,7 @@
 import re
 import casefy
 from dataclasses import dataclass
+
 from beartype.door import is_bearable
 from collections.abc import Mapping, Sequence, Callable
 from typing import (

serde/de.py

@@ -12,6 +12,7 @@
 import typing
 import jinja2
 from collections.abc import Callable, Sequence, Iterable
+
 from beartype import beartype, BeartypeConf
 from beartype.door import is_bearable
 from beartype.roar import BeartypeCallHintParamViolation
@@ -86,19 +87,31 @@
     raise_unsupported_type,
     union_func_name,
 )
-from .numpy import (
-    deserialize_numpy_array,
-    deserialize_numpy_scalar,
-    deserialize_numpy_array_direct,
-    deserialize_numpy_jaxtyping_array,
-    is_numpy_array,
-    is_numpy_jaxtyping,
-    is_numpy_scalar,
-)
+
+# Lazy numpy imports to improve startup time
 
 __all__ = ["deserialize", "is_deserializable", "from_dict", "from_tuple"]
 
 
+# Lazy numpy import wrappers to improve startup time
+def _is_numpy_array(typ: Any) -> bool:
+    from .numpy import is_numpy_array
+
+    return is_numpy_array(typ)
+
+
+def _is_numpy_scalar(typ: Any) -> bool:
+    from .numpy import is_numpy_scalar
+
+    return is_numpy_scalar(typ)
+
+
+def _is_numpy_jaxtyping(typ: Any) -> bool:
+    from .numpy import is_numpy_jaxtyping
+
+    return is_numpy_jaxtyping(typ)
+
+
 DeserializeFunc = Callable[[type[Any], Any], Any]
 """ Interface of Custom deserialize function. """
 
@@ -490,7 +503,9 @@ def deserializable_to_obj(cls: type[T]) -> T:
                 res = {
                     thisfunc(type_args(c)[0], k): thisfunc(type_args(c)[1], v) for k, v in o.items()
                 }
-        elif is_numpy_array(c):
+        elif _is_numpy_array(c):
+            from .numpy import deserialize_numpy_array_direct
+
             res = deserialize_numpy_array_direct(c, o)
         elif is_datetime(c):
             res = c.fromisoformat(o)
@@ -752,13 +767,19 @@ def render(self, arg: DeField[Any]) -> str:
             res = self.tuple(arg)
         elif is_enum(arg.type):
             res = self.enum(arg)
-        elif is_numpy_scalar(arg.type):
+        elif _is_numpy_scalar(arg.type):
+            from .numpy import deserialize_numpy_scalar
+
             self.import_numpy = True
             res = deserialize_numpy_scalar(arg)
-        elif is_numpy_array(arg.type):
+        elif _is_numpy_array(arg.type):
+            from .numpy import deserialize_numpy_array
+
             self.import_numpy = True
             res = deserialize_numpy_array(arg)
-        elif is_numpy_jaxtyping(arg.type):
+        elif _is_numpy_jaxtyping(arg.type):
+            from .numpy import deserialize_numpy_jaxtyping_array
+
             self.import_numpy = True
             res = deserialize_numpy_jaxtyping_array(arg)
         elif is_union(arg.type):

serde/json.py

@@ -7,7 +7,8 @@
 from .compat import T
 from .de import Deserializer, from_dict
 from .se import Serializer, to_dict
-from .numpy import encode_numpy
+
+# Lazy numpy imports to improve startup time
 
 try:  # pragma: no cover
     import orjson
@@ -25,6 +26,8 @@ def json_loads(s: Union[str, bytes], **opts: Any) -> Any:
 
     def json_dumps(obj: Any, **opts: Any) -> str:
         if "default" not in opts:
+            from .numpy import encode_numpy
+
             opts["default"] = encode_numpy
         # compact output
         ensure_ascii = opts.pop("ensure_ascii", False)

serde/msgpack.py

@@ -10,7 +10,8 @@
 from .compat import T
 from .compat import SerdeError
 from .de import Deserializer, from_dict, from_tuple
-from .numpy import encode_numpy
+
+# Lazy numpy imports to improve startup time
 from .se import Serializer, to_dict, to_tuple
 
 __all__ = ["from_msgpack", "to_msgpack"]
@@ -22,6 +23,8 @@ def serialize(
         cls, obj: Any, use_bin_type: bool = True, ext_type_code: Optional[int] = None, **opts: Any
     ) -> bytes:
         if "default" not in opts:
+            from .numpy import encode_numpy
+
             opts["default"] = encode_numpy
         if ext_type_code is not None:
             obj_bytes = msgpack.packb(obj, use_bin_type=use_bin_type, **opts)

serde/se.py

@@ -14,6 +14,7 @@
 from dataclasses import dataclass, is_dataclass
 from typing import TypeVar, Literal, Generic, Optional, Any, Union
 from collections.abc import Callable, Iterable, Iterator
+
 from beartype import beartype, BeartypeConf
 from beartype.door import is_bearable
 from typing_extensions import dataclass_transform
@@ -75,19 +76,37 @@
     union_func_name,
     GLOBAL_CLASS_SERIALIZER,
 )
-from .numpy import (
-    is_numpy_array,
-    is_numpy_jaxtyping,
-    is_numpy_datetime,
-    is_numpy_scalar,
-    serialize_numpy_array,
-    serialize_numpy_datetime,
-    serialize_numpy_scalar,
-)
+
+# Lazy numpy imports to improve startup time
 
 __all__ = ["serialize", "is_serializable", "to_dict", "to_tuple"]
 
 
+# Lazy numpy import wrappers to improve startup time
+def _is_numpy_array(typ: Any) -> bool:
+    from .numpy import is_numpy_array
+
+    return is_numpy_array(typ)
+
+
+def _is_numpy_scalar(typ: Any) -> bool:
+    from .numpy import is_numpy_scalar
+
+    return is_numpy_scalar(typ)
+
+
+def _is_numpy_jaxtyping(typ: Any) -> bool:
+    from .numpy import is_numpy_jaxtyping
+
+    return is_numpy_jaxtyping(typ)
+
+
+def _is_numpy_datetime(typ: Any) -> bool:
+    from .numpy import is_numpy_datetime
+
+    return is_numpy_datetime(typ)
+
+
 SerializeFunc = Callable[[type[Any], Any], Any]
 """ Interface of Custom serialize function. """
 
@@ -775,13 +794,21 @@ def render(self, arg: SeField[Any]) -> str:
             res = self.tuple(arg)
         elif is_enum(arg.type):
             res = self.enum(arg)
-        elif is_numpy_datetime(arg.type):
+        elif _is_numpy_datetime(arg.type):
+            from .numpy import serialize_numpy_datetime
+
             res = serialize_numpy_datetime(arg)
-        elif is_numpy_scalar(arg.type):
+        elif _is_numpy_scalar(arg.type):
+            from .numpy import serialize_numpy_scalar
+
             res = serialize_numpy_scalar(arg)
-        elif is_numpy_array(arg.type):
+        elif _is_numpy_array(arg.type):
+            from .numpy import serialize_numpy_array
+
             res = serialize_numpy_array(arg)
-        elif is_numpy_jaxtyping(arg.type):
+        elif _is_numpy_jaxtyping(arg.type):
+            from .numpy import serialize_numpy_array
+
             res = serialize_numpy_array(arg)
         elif is_primitive(arg.type):
             res = self.primitive(arg)