spasmlang is a simple Python assembly language. It is essentially a high-level interface on top of the bytecode package that allows you to generate bytecode from a simple assembly-like syntax.

Table of Contents

• Installation
• Usage
• Examples
• License

pip install spasmlang

The spasmlang package provides a single class, Assembly, that allows you to generate bytecode from a simple assembly-like syntax. See the examples below for a taste of its API.

You can also use the spasm command-line utility to compile assembly files directly to Python bytecode:

spasm example.pya  # generates example.pyc

This is how the classic "Hello, World!" program looks like, targeting the CPython 3.12 bytecode:

from spasm import Assembly

asm = Assembly()
asm.parse(
    r"""
    push_null
    load_const          print
    load_const          "Hello, World!"
    call                1
    return_value
    """
)
exec(asm.compile())

This is how you can compile the file example.pya to example.pyc to create a "Hello, World!" module, again targeting CPython 3.11:

# example.pya
    resume      0
    push_null
    load_name   $print
    load_const  "Hello, spasm!"
    precall     1
    call        1
    pop_top
    load_const  None
    return_value

Compile the assembly code with (assuming that you have installed spasmlang with CPython 3.11)

spasm example.pya

and then execute the generated module with e.g.

python3.11 -m example

This example shows how to create a module that exports a greet function that takes one argument, targeting CPython 3.11:

# greet.pya

code greet(who)
    resume                      0
    load_global                 (True, "print")
    load_const                  "Hello, "
    load_fast                   $who
    format_value                0
    build_string                2
    precall                     1
    call                        1
    return_value
end

    resume 0
    load_const                  .greet
    make_function               0
    store_name                  $greet
    load_const                  None
    return_value

Again, compile the assembly code with

spasm greet.pya

and test it with

$ python3.11 -c "from greet import greet; greet('spasmlang')"
Hello, spasmlang

spasmlang is distributed under the terms of the MIT license.