Mojo struct

PythonModuleBuilder

struct PythonModuleBuilder

A builder for creating Python modules with Mojo function and type bindings.

This builder provides a high-level API for declaring Python bindings for Mojo functions and types within a Python module. It manages the registration of functions, types, and their associated metadata, then finalizes everything into a complete Python module object.

The builder follows a declarative pattern where you:

Create a builder instance with a module name
Add function bindings using def_function(), def_py_function(), def_py_c_function()
Add type bindings using add_type[T]() and configure them
Call finalize() to finish building the Python module.

Example:

from python.bindings import PythonModuleBuilder

var builder = PythonModuleBuilder("my_module")
builder.def_function[my_func]("my_func", "Documentation for my_func")

_ = builder.add_type[MyType]("MyType").def_method[my_method]("my_method")

var module = builder.finalize()
from python.bindings import PythonModuleBuilder

var builder = PythonModuleBuilder("my_module")
builder.def_function[my_func]("my_func", "Documentation for my_func")

_ = builder.add_type[MyType]("MyType").def_method[my_method]("my_method")

var module = builder.finalize()

Note: After calling finalize(), the builder's internal state is cleared and it should not be reused for creating additional modules.

TODO: This should be enforced programmatically in the future.

Fields

module (TypedPythonObject[__init__[__mlir_type.!kgen.string]("Module")]): The Python module being built.
functions (List[PyMethodDef]): List of function definitions that will be exposed in the module.
type_builders (List[PythonTypeBuilder]): List of type builders for types that will be exposed in the module.

Implemented traits

AnyType, UnknownDestructibility

Methods

`init`

__init__(out self, name: StringSlice[StaticConstantOrigin])

Construct a Python module builder with the given module name.

Args:

name (StringSlice[StaticConstantOrigin]): The name of the module.

Raises:

If the module creation fails.

__init__(out self, module: TypedPythonObject[__init__[__mlir_type.!kgen.string]("Module")])

Construct a Python module builder with the given module.

Args:

module (TypedPythonObject[__init__[__mlir_type.!kgen.string]("Module")]): The module to build.

`add_type`

add_type[T: Movable & Defaultable & Representable & TypeIdentifiable](mut self, type_name: StringSlice[StaticConstantOrigin]) -> ref [*[0,0].type_builders] PythonTypeBuilder

Add a type to the module and return a builder for it.

Parameters:

T (Movable & Defaultable & Representable & TypeIdentifiable): The mojo type to bind in the module.

Args:

type_name (StringSlice[StaticConstantOrigin]): The name of the type to expose in the module.

Returns:

A reference to a type builder registered in the module builder.

`def_py_c_function`

def_py_c_function(mut self, func: fn(PyObjectPtr, PyObjectPtr) -> PyObjectPtr, func_name: StringSlice[StaticConstantOrigin], docstring: StringSlice[StaticConstantOrigin] = StringSlice())

Declare a binding for a function with PyCFunction signature in the module.

Args:

func (fn(PyObjectPtr, PyObjectPtr) -> PyObjectPtr): The function to declare a binding for.
func_name (StringSlice[StaticConstantOrigin]): The name with which the function will be exposed in the module.
docstring (StringSlice[StaticConstantOrigin]): The docstring for the function in the module.

`def_py_function`

def_py_function[func: fn(mut PythonObject, mut TypedPythonObject[__init__[__mlir_type.!kgen.string]("Tuple")]) -> PythonObject](mut self, func_name: StringSlice[StaticConstantOrigin], docstring: StringSlice[StaticConstantOrigin] = StringSlice())

Declare a binding for a function with PyFunction signature in the module.

Parameters:

func (fn(mut PythonObject, mut TypedPythonObject[__init__[__mlir_type.!kgen.string]("Tuple")]) -> PythonObject): The function to declare a binding for.

Args:

func_name (StringSlice[StaticConstantOrigin]): The name with which the function will be exposed in the module.
docstring (StringSlice[StaticConstantOrigin]): The docstring for the function in the module.

def_py_function[func: fn(mut PythonObject, mut TypedPythonObject[__init__[__mlir_type.!kgen.string]("Tuple")]) raises -> PythonObject](mut self, func_name: StringSlice[StaticConstantOrigin], docstring: StringSlice[StaticConstantOrigin] = StringSlice())

Declare a binding for a function with PyFunctionRaising signature in the module.

Parameters:

func (fn(mut PythonObject, mut TypedPythonObject[__init__[__mlir_type.!kgen.string]("Tuple")]) raises -> PythonObject): The function to declare a binding for.

Args:

func_name (StringSlice[StaticConstantOrigin]): The name with which the function will be exposed in the module.
docstring (StringSlice[StaticConstantOrigin]): The docstring for the function in the module.

`def_function`

def_function[func: fn() raises -> PythonObject](mut self, func_name: StringSlice[StaticConstantOrigin], docstring: StringSlice[StaticConstantOrigin] = StringSlice())