#!/usr/bin/env -S python3 -I

# /// script

# requires-python = ">=3.14"

# ///

# This script generates Lib/snippets/whats_left_data.py with these variables defined:

# expected_methods - a dictionary mapping builtin objects to their methods

# cpymods - a dictionary mapping module names to their contents, including

# the members of native classes as "Class.member"

# libdir - the location of RustPython's Lib/ directory.

#

# TODO: include this:

# which finds all modules it has available and

# creates a Python dictionary mapping module names to their contents, which is

# in turn used to generate a second Python script that also finds which modules

# it has available and compares that against the first dictionary we generated.

# We then run this second generated script with RustPython.

import argparse

import inspect

import json

import os

import platform

import re

import subprocess

import sys

import types

import warnings

from pydoc import ModuleScanner

if not sys.flags.isolated:

print("running without -I option.")

print("python -I scripts/whats_left.py")

exit(1)

GENERATED_FILE = "extra_tests/not_impl.py"

implementation = platform.python_implementation()

if implementation != "CPython":

sys.exit(f"whats_left.py must be run under CPython, got {implementation} instead")

if sys.version_info[:2] < (3, 14):

sys.exit(

f"whats_left.py must be run under CPython 3.14 or newer, got {implementation} {sys.version} instead. If you have uv, try `uv run python -I scripts/whats_left.py` to select a proper Python interpreter easier."

)

def parse_args():

parser = argparse.ArgumentParser(description="Process some integers.")

parser.add_argument(

"--signature",

action="store_true",

help="print functions whose signatures don't match CPython's",

)

parser.add_argument(

"--doc",

action="store_true",

help="print elements whose __doc__ don't match CPython's",

)

parser.add_argument(

"--json",

action="store_true",

help="print output as JSON (instead of line by line)",

)

parser.add_argument(

"--no-default-features",

action="store_true",

help="disable default features when building RustPython",

)

parser.add_argument(

"--features",

action="append",

help="which features to enable when building RustPython (default: [])",

default=[],

)

parser.add_argument(

"--rustpython",

help="use this RustPython executable instead of building one with cargo",

)

args = parser.parse_args()

return args

args = parse_args()

# CPython specific modules (mostly consisting of templates/tests)

CPYTHON_SPECIFIC_MODS = {

"xxmodule",

"xxsubtype",

"xxlimited",

"_xxtestfuzz",

"_testbuffer",

"_testcapi",

"_testimportmultiple",

"_testinternalcapi",

"_testmultiphase",

"_testlimitedcapi",

}

IGNORED_MODULES = {"this", "antigravity"} | CPYTHON_SPECIFIC_MODS

sys.path = [

path

for path in sys.path

if ("site-packages" not in path and "dist-packages" not in path)

]

def attr_is_not_inherited(type_, attr):

"""

returns True if type_'s attr is not inherited from any of its base classes

"""

return attr in type_.__dict__

def extra_info(obj):

import sys

class _OrderedSet:

"""Set repr with sorted elements, so hash order does not change it."""

def __init__(self, items, braces):

self.items = items

self.braces = braces

def __repr__(self):

if not self.items:

return "set()" if self.braces else "frozenset()"

body = ", ".join(sorted(repr(item) for item in self.items))

if self.braces:

return "{" + body + "}"

return "frozenset({" + body + "})"

def canon_default(param):

default = param.default

# The interpreter path, version tuple, and install scheme differ per process.

if isinstance(default, str) and default == sys.executable:

return "<sys.executable>"

if default is sys.version_info:

return "<sys.version_info>"

if param.name == "scheme" and isinstance(default, str):

import sysconfig

if default == sysconfig.get_default_scheme():

return "<sysconfig.get_default_scheme()>"

if isinstance(default, frozenset):

return _OrderedSet(default, False)

if isinstance(default, set):

return _OrderedSet(default, True)

return default

def stable_signature(target):

sig = inspect.signature(target)

params = []

changed = False

for param in sig.parameters.values():

if param.default is not inspect.Parameter.empty:

default = canon_default(param)

if default is not param.default:

param = param.replace(default=default)

changed = True

params.append(param)

if changed:

sig = sig.replace(parameters=params)

# remove function memory addresses

return re.sub(r" at 0x[0-9A-Fa-f]+", " at 0xdeadbeef", str(sig))

if callable(obj):

doc = inspect.getdoc(obj)

try:

return {

"sig": stable_signature(obj),

"doc": doc,

}

except Exception as e:

exception = repr(e)

# CPython uses ' RustPython uses "

if exception.replace('"', "'").startswith("ValueError('no signature found"):

return {

"sig": "ValueError('no signature found')",

"doc": doc,

}

return {

"sig": exception,

"doc": doc,

}

return {

"sig": None,

"doc": None,

}

def name_sort_key(name):

if name == "builtins":

return ""

if name[0] == "_":

return name[1:] + "1"

return name + "2"

BUILTIN_TYPES = [

bool,

bytearray,

bytes,

complex,

dict,

enumerate,

filter,

float,

frozenset,

int,

list,

map,

memoryview,

range,

set,

slice,

str,

super,

tuple,

object,

zip,

classmethod,

staticmethod,

property,

Exception,

BaseException,

]

# CPython's per-class annotations cache and its vectorcall C API offset

CPYTHON_INTERNAL_ATTRS = {"__annotations_cache__", "__vectorcalloffset__"}

def own_attrs(typ):

attrs = []

for attr in dir(typ):

if attr in CPYTHON_INTERNAL_ATTRS:

continue

# Skip attributes in dir() but not actually accessible (e.g., descriptor that raises)

if not hasattr(typ, attr):

continue

if attr_is_not_inherited(typ, attr):

attrs.append((attr, extra_info(getattr(typ, attr))))

return attrs

def is_native_class(obj):

# A class statement records __firstlineno__. A class made by calling

# type(), like a namedtuple, still has Python functions.

if not isinstance(obj, type) or "__firstlineno__" in obj.__dict__:

return False

for value in obj.__dict__.values():

if isinstance(value, (classmethod, staticmethod)):

value = value.__func__

if isinstance(value, property):

value = value.fget

if isinstance(value, types.FunctionType):

return False

return True

def gen_methods():

objects = [t.__name__ for t in BUILTIN_TYPES]

objects.append("type(None)")

iters = [

"type(bytearray().__iter__())",

"type(bytes().__iter__())",

"type(dict().__iter__())",

"type(dict().values().__iter__())",

"type(dict().items().__iter__())",

"type(dict().values())",

"type(dict().items())",

"type(set().__iter__())",

"type(list().__iter__())",

"type(range(0).__iter__())",

"type(str().__iter__())",

"type(tuple().__iter__())",

"type(memoryview(bytearray(b'0')).__iter__())",

]

methods = {}

for typ_code in objects + iters:

typ = eval(typ_code)

methods[typ.__name__] = (typ_code, extra_info(typ), own_attrs(typ))

output = "expected_methods = {\n"

for name in sorted(methods.keys(), key=name_sort_key):

typ_code, extra, attrs = methods[name]

output += f" '{name}': ({typ_code}, {extra!r}, [\n"

for attr, attr_extra in attrs:

output += f" ({attr!r}, {attr_extra!r}),\n"

output += " ]),\n"

if typ_code != objects[-1]:

output += "\n"

output += "}\n\n"

return output

def scan_modules():

"""taken from the source code of help('modules')

https://github.com/python/cpython/blob/63298930fb531ba2bb4f23bc3b915dbf1e17e9e1/Lib/pydoc.py#L2178"""

modules = {}

def callback(path, modname, desc, modules=modules):

if modname and modname[-9:] == ".__init__":

modname = modname[:-9] + " (package)"

if modname.find(".") < 0:

modules[modname] = 1

def onerror(modname):

callback(None, modname, None)

with warnings.catch_warnings():

# ignore warnings from importing deprecated modules

warnings.simplefilter("ignore")

ModuleScanner().run(callback, onerror=onerror)

return list(modules.keys())

def import_module(module_name):

import io

from contextlib import redirect_stdout

# Importing modules causes ('Constant String', 2, None, 4) and

# "Hello world!" to be printed to stdout.

f = io.StringIO()

with warnings.catch_warnings(), redirect_stdout(f):

# ignore warnings caused by importing deprecated modules

warnings.filterwarnings("ignore", category=DeprecationWarning)

try:

module = __import__(module_name)

except Exception as e:

return e

return module

def is_child(module, item):

import inspect

item_mod = inspect.getmodule(item)

return item_mod is module

def dir_of_mod_or_error(module_name, keep_other=True):

module = import_module(module_name)

if isinstance(module, Exception):

return module

item_names = sorted(set(dir(module)))

result = {}

for item_name in item_names:

# eval() adds __builtins__ to its globals, and inspect.signature() evals

# defaults in the module's namespace, so whether it exists depends on

# what was inspected before.

if item_name == "__builtins__":

continue

if item_name == "__doc__":

# extra_info() reports a docstring for a callable only, and a module

# is not one. getdoc() matches how a callable's is normalized.

result[item_name] = {"sig": None, "doc": inspect.getdoc(module)}

continue

item = getattr(module, item_name)

# don't repeat items imported from other modules

if keep_other or is_child(module, item) or inspect.getmodule(item) is None:

result[item_name] = extra_info(item)

return result

def _is_decimal_fallback_item(item):

"""Items that belong to the pure decimal module, not an imported helper."""

if inspect.ismodule(item):

return False

declared = getattr(item, "__module__", None)

if declared in {"decimal", "_pydecimal"}:

return True

return declared is None and inspect.getmodule(item) is None

def _expand_class_members(dir_result, module):

for item_name in list(dir_result):

if "." in item_name:

continue

item = getattr(module, item_name)

if (

isinstance(item, type)

and item not in BUILTIN_TYPES

and getattr(item, "__name__", None) == item_name

):

for attr, info in own_attrs(item):

dir_result[f"{item_name}.{attr}"] = info

def _pure_decimal_baseline(wrapper):

"""Signatures and docs from `_pydecimal`, with the wrapper module docstring."""

import _pydecimal

result = {}

for item_name in sorted(set(dir(_pydecimal))):

if item_name == "__builtins__":

continue

if item_name == "__doc__":

result[item_name] = {"sig": None, "doc": inspect.getdoc(wrapper)}

continue

item = getattr(_pydecimal, item_name)

if not _is_decimal_fallback_item(item):

continue

result[item_name] = extra_info(item)

_expand_class_members(result, _pydecimal)

return result

def gen_modules():

# check name because modules listed have side effects on import,

# e.g. printing something or opening a webpage

modules = {}

for mod_name in sorted(scan_modules(), key=name_sort_key):

if mod_name in IGNORED_MODULES:

continue

# decimal's accelerated types are not the implementation under test.

if mod_name == "decimal":

module = import_module(mod_name)

if isinstance(module, Exception):

print(

f"!!! {mod_name} skipped because {type(module).__name__}: {str(module)}",

file=sys.stderr,

)

continue

modules[mod_name] = _pure_decimal_baseline(module)

continue

# when generating CPython list, ignore items defined by other modules

dir_result = dir_of_mod_or_error(mod_name, keep_other=False)

if isinstance(dir_result, Exception):

print(

f"!!! {mod_name} skipped because {type(dir_result).__name__}: {str(dir_result)}",

file=sys.stderr,

)

continue

module = import_module(mod_name)

for item_name in list(dir_result):

item = getattr(module, item_name)

# an alias such as array.ArrayType is scanned under its real name

if (

is_native_class(item)

and item not in BUILTIN_TYPES

and item.__name__ == item_name

):

for attr, info in own_attrs(item):

dir_result[f"{item_name}.{attr}"] = info

modules[mod_name] = dir_result

return modules

output = """\

# WARNING: THIS IS AN AUTOMATICALLY GENERATED FILE

# EDIT extra_tests/not_impl_gen.sh, NOT THIS FILE.

# RESULTS OF THIS TEST DEPEND ON THE CPYTHON

# VERSION AND PYTHON ENVIRONMENT USED

# TO RUN not_impl_mods_gen.py

"""

output += gen_methods()

output += f"""

cpymods = {gen_modules()!r}

libdir = {os.path.abspath("Lib/").encode("utf8")!r}

"""

# Copy the source code of functions we will reuse in the generated script

REUSED = [

attr_is_not_inherited,

extra_info,

dir_of_mod_or_error,

import_module,

is_child,

]

for fn in REUSED:

output += "".join(inspect.getsourcelines(fn)[0]) + "\n\n"

# Prevent missing variable linter errors from compare()

expected_methods = {}

cpymods = {}

libdir = ""

# This function holds the source code that will be run under RustPython

def compare():

import inspect

import io

import json

import os

import platform

import re

import sys

import warnings

from contextlib import redirect_stdout

def sig_mismatch(rustpy_sig, cpython_sig):

# A signature CPython cannot produce is never a mismatch; having one is fine.

if cpython_sig is None or cpython_sig.startswith("ValueError("):

return False

return rustpy_sig != cpython_sig

def method_incompatibility_reason(typ, method_name, real_method_value):

has_method = hasattr(typ, method_name)

if not has_method:

return ""

is_inherited = not attr_is_not_inherited(typ, method_name)

# Inheriting something that reads the same as CPython's own member

# leaves nothing to implement.

if is_inherited and extra_info(getattr(typ, method_name)) != real_method_value:

return "(inherited)"

return None

not_implementeds = {}

mismatched_methods = {}

mismatched_method_docs = {}

for name, (typ, real_value, methods) in expected_methods.items():

missing_methods = {}

for method, real_method_value in methods:

reason = method_incompatibility_reason(typ, method, real_method_value)

if reason is not None:

missing_methods[method] = reason

continue

# A method that exists but differs is a mismatch, not a missing one.

value = extra_info(getattr(typ, method))

item = f"{name}.{method}"

if sig_mismatch(value["sig"], real_method_value["sig"]):

mismatched_methods.setdefault(name, []).append(

(item, value["sig"], real_method_value["sig"])

)

if value["doc"] != real_method_value["doc"]:

mismatched_method_docs.setdefault(name, []).append(

(item, value["doc"], real_method_value["doc"])

)

if missing_methods:

not_implementeds[name] = missing_methods

if platform.python_implementation() == "CPython":

if not_implementeds:

sys.exit(

f"ERROR: CPython should have all the methods but missing: {not_implementeds}"

)

mod_names = [

name.decode()

for name, ext in map(os.path.splitext, os.listdir(libdir))

if ext == b".py" or os.path.isdir(os.path.join(libdir, name))

]

mod_names += list(sys.builtin_module_names)

# Remove easter egg modules

mod_names = sorted(set(mod_names) - {"this", "antigravity"})

rustpymods = {mod: dir_of_mod_or_error(mod) for mod in mod_names}

result = {

"cpython_modules": {},

"implemented": {},

"not_implemented": {},

"failed_to_import": {},

"missing_items": {},

# builtin types first, keyed by type name, then modules

"mismatched_items": mismatched_methods,

"mismatched_doc_items": mismatched_method_docs,

}

for modname, cpymod in cpymods.items():

rustpymod = rustpymods.get(modname)

if rustpymod is None:

result["not_implemented"][modname] = None

elif isinstance(rustpymod, Exception):

result["failed_to_import"][modname] = (

f"{rustpymod.__class__.__name__}: {rustpymod}"

)

else:

module = import_module(modname)

skipped = set()

inherited = set()

for item in cpymod:

cls_name, dot, attr = item.partition(".")

if not dot:

continue

cls = getattr(module, cls_name, None)

if not isinstance(cls, type):

# The class line already reports a missing class or one

# implemented as something else.

skipped.add(item)

elif not hasattr(cls, attr):

continue

elif attr_is_not_inherited(cls, attr):

rustpymod[item] = extra_info(getattr(cls, attr))

elif extra_info(getattr(cls, attr)) == cpymod[item]:

rustpymod[item] = cpymod[item]

else:

inherited.add(item)

implemented_items = sorted(set(cpymod) & set(rustpymod))

mod_missing_items = set(cpymod) - set(rustpymod) - skipped

mod_missing_items = sorted(

f"{modname}.{item}" + (" (inherited)" if item in inherited else "")

for item in mod_missing_items

)

mod_mismatched_items = [

(f"{modname}.{item}", rustpymod[item]["sig"], cpymod[item]["sig"])

for item in implemented_items

if sig_mismatch(rustpymod[item]["sig"], cpymod[item]["sig"])

]

mod_mismatched_doc_items = [

(f"{modname}.{item}", rustpymod[item]["doc"], cpymod[item]["doc"])

for item in implemented_items

if rustpymod[item]["doc"] != cpymod[item]["doc"]

]

if mod_missing_items:

result["missing_items"][modname] = mod_missing_items

if mod_mismatched_items:

result["mismatched_items"][modname] = mod_mismatched_items

if mod_mismatched_doc_items:

result["mismatched_doc_items"][modname] = mod_mismatched_doc_items

if not (mod_missing_items or mod_mismatched_items):

result["implemented"][modname] = None

result["cpython_modules"] = cpymods

result["not_implementeds"] = not_implementeds

print(json.dumps(result))

def remove_one_indent(s):

indent = " "

return s[len(indent) :] if s.startswith(indent) else s

compare_src = inspect.getsourcelines(compare)[0][1:]

output += "".join(remove_one_indent(line) for line in compare_src)

with open(GENERATED_FILE, "w", encoding="utf-8") as f:

f.write(output + "\n")

def resolve_rustpython(path):

if os.path.isfile(path):

return path

if os.name == "nt" and not path.lower().endswith(".exe"):

exe = path + ".exe"

if os.path.isfile(exe):

return exe

sys.exit(f"RustPython executable not found: {path}")

if args.rustpython:

rustpython_run_command = [resolve_rustpython(args.rustpython), GENERATED_FILE]

else:

cargo_build_command = ["cargo", "build", "--release"]

if args.no_default_features:

cargo_build_command.append("--no-default-features")

joined_features = ",".join(args.features)

if args.features:

cargo_build_command.extend(["--features", joined_features])

subprocess.run(cargo_build_command, check=True)

rustpython_run_command = ["cargo", "run", "--release"]

if args.no_default_features:

rustpython_run_command.append("--no-default-features")

if args.features:

rustpython_run_command.extend(["--features", joined_features])

rustpython_run_command.extend(["-q", "--", GENERATED_FILE])

result = subprocess.run(

rustpython_run_command,

env={**os.environ.copy(), "RUSTPYTHONPATH": "Lib"},

text=True,

capture_output=True,

)

# The last line should be json output, the rest of the lines can contain noise

# because importing certain modules can print stuff to stdout/stderr

print(result.stderr, file=sys.stderr)

result = json.loads(result.stdout.splitlines()[-1])

if args.json:

print(json.dumps(result))

sys.exit()

# missing entire modules

print("# modules")

for modname in result["not_implemented"]:

print(modname, "(entire module)")

for modname, exception in result["failed_to_import"].items():

print(f"{modname} (exists but not importable: {exception})")

# missing from builtins

print("\n# builtin items")

for module, missing_methods in result["not_implementeds"].items():

for method, reason in missing_methods.items():

print(f"{module}.{method}" + (f" {reason}" if reason else ""))

# missing from modules

print("\n# stdlib items")

for modname, missing in result["missing_items"].items():

for item in missing:

print(item)

if args.signature:

print("\n# mismatching signatures (warnings)")

for modname, mismatched in result["mismatched_items"].items():

for i, (item, rustpy_value, cpython_value) in enumerate(mismatched):

if rustpy_value is None or rustpy_value.startswith("ValueError("):

rustpy_value = f" {rustpy_value}"

print(f"{item}{rustpy_value}")

if cpython_value is None:

cpython_value = f" {cpython_value}"

print(f"{' ' * len(item)}{cpython_value}")

if i < len(mismatched) - 1:

print()

if args.doc:

print("\n# mismatching `__doc__`s (warnings)")

for modname, mismatched in result["mismatched_doc_items"].items():

for item, rustpy_doc, cpython_doc in mismatched:

print(f"{item} {repr(rustpy_doc)} != {repr(cpython_doc)}")

print()

print("# summary")

for error_type, modules in result.items():

print("# ", error_type, len(modules))