Modules

This page is the catalogue. Every name you can import in gopy today is listed below, with a note on how complete the port is and where the source lives. The wiring lives in stdlibinit/registry.go; each module's init() block calls imp.AppendInittab(name, factory) to register its name.

Status legend

• Complete. Every public API is wired and behaves like CPython 3.14.
• Partial. The module imports and the common path works, but some functions raise NotImplementedError or are missing.
• Stub. The name is registered so import succeeds; most attributes are unimplemented.

Catalogue

Core and built-ins

Module	State	Source	Notes
builtins	Complete	module/builtins/	print, len, range, exception types, etc.
sys	Complete	module/sys/	argv, path, modules, version_info.
_io	Complete	module/_io/	C-level I/O classes; backs io.
io	Complete	module/io/	Text/binary I/O wrappers.
errno	Complete	module/errno/	Errno constants.
signal	Complete	module/signal/	Signal handlers and constants.
gc	Complete	module/gc/	gc.collect, generation thresholds.
_warnings	Complete	module/_warnings/	The C side of warnings.
warnings	Complete	module/warnings/	Filter management.

Numeric and functional

Module	State	Source	Notes
math	Complete	module/math/	Trig, log, gamma, isqrt, isfinite.
_functools	Complete	module/_functools/	C side of functools.
functools	Complete	module/functools/	reduce, partial, lru_cache, ...
_operator	Complete	module/_operator/	itemgetter, attrgetter, ops.

Containers and algorithms

Module	State	Source	Notes
collections	Complete	module/_collections/	deque, OrderedDict, Counter, ChainMap.
_heapq	Partial	module/_heapq/	Core heap ops; some helpers pending.
_bisect	Partial	module/_bisect/	bisect_left, bisect_right.
_itertools	Partial	module/_itertools/	Several iterators pending.

Text and pattern matching

Module	State	Source	Notes
re	Complete	module/re/	Full re API.
_sre	Complete	module/_sre/	Pattern engine; see spec 1703 for details.
_codecs	Complete	module/_codecs/	UTF-8 / 16 / 32, latin-1, ASCII.
_string	Partial	module/_string/	The C helpers behind string.Formatter.
difflib	Complete	module/difflib/	SequenceMatcher, unified_diff.
fnmatch	Complete	module/fnmatch/	Shell-style wildcards.
_tokenize	Complete	module/_tokenize/	Tokeniser exposed to Python.

Data formats

Module	State	Source	Notes
_json	Complete	module/_json/	loads, dumps, the encoder/decoder.
_csv	Complete	module/_csv/	Reader / writer / dialect.
_hashlib	Complete	module/_hashlib/	MD5, SHA-1, SHA-256, etc.
zlib	Complete	module/zlib/	Deflate / inflate.

OS, I/O, network

Module	State	Source	Notes
os	Complete	module/os/	path, environ, getcwd, etc.
_socket	Complete	module/_socket/	Low-level sockets.
socket	Complete	module/socket/	High-level wrappers.
_stat	Partial	module/_stat/	S_ISDIR, mode bits.
_posixsubprocess	Stub	module/_posixsubprocess/	Registered; runtime not yet usable.

Concurrency and contexts

Module	State	Source	Notes
_thread	Partial	module/_thread/	Lock, start_new_thread, ident.
contextvars	Complete	module/contextvars/	ContextVar, copy_context.
contextlib	Complete	module/contextlib/	contextmanager, suppress, ExitStack.

Date and time

Module	State	Source	Notes
_time	Partial	module/_time/	time, monotonic, sleep. Pieces pending.
_datetime	Partial	module/_datetime/	date, datetime, timedelta. timezones partial.

Introspection, types, weakrefs

Module	State	Source	Notes
traceback	Complete	module/traceback/	format_exc, extract_stack.
types	Complete	module/types/	FunctionType, MappingProxyType.
_weakref	Complete	module/_weakref/	The C side of weakref.
weakref	Complete	module/weakref/	ref, WeakValueDictionary, ...

Class machinery

Module	State	Source	Notes
_abc	Partial	module/_abc/	ABCMeta core; subclass cache partial.
dataclasses	Complete	module/dataclasses/	@dataclass, field, replace.

Tooling

Module	State	Source	Notes
argparse	Complete	module/argparse/	Subset matching CPython output.
_opcode	Partial	module/_opcode/	Used by dis and the compiler.
_random	Stub	module/_random/	Registered; Mersenne Twister pending.
_uuid	Stub	module/_uuid/	Registered; native UUID pending.

What is not here yet

The following commonly used modules are not in gopy today. Track the project issues for status. If your service needs one, file a request: it helps us prioritise.

• asyncio, selectors
• multiprocessing, the full threading module
• ssl, hashlib (the high-level wrapper)
• subprocess
• urllib.*, http.*, email
• pathlib
• sqlite3, dbm
• logging (the full module; bare print works)
• unittest, pytest

Adding your own

A Go author can register a new module in their own package with imp.AppendInittab. See Embedding for the pattern.

Reference

• stdlibinit/stdlibinit.go. The blank-import wiring.
• stdlibinit/registry.go. The per-module init manifest.
• imp/inittab.go. The registration API.