goodboy
/
tractor
1
0
Fork 2
Code Issues 5 Pull Requests 6 Packages Projects Releases Wiki Activity
tractor/tractor/devx/__init__.py

79 lines
2.6 KiB
Python
Raw Normal View History

Kick off `.devx` subpkg for our dev tools B) Where `.devx` is "developer experience", a hopefully broad enough subpkg name for all the slick stuff planned to augment working on the actor runtime :boom: Move the `._debug` module into the new subpkg and adjust rest of core code base to reflect import path change. Also add a new `.devx._debug.open_crash_handler()` manager for wrapping any sync code outside a `trio.run()` which is handy for eventual CLI addons for popular frameworks like `click`/`typer`.
2023-09-28 18:14:50 +00:00
# tractor: structured concurrent "actors".
# Copyright 2018-eternity Tyler Goodlet.
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
"""
Runtime "developer experience" utils and addons to aid our
(advanced) users and core devs in building distributed applications
and working with/on the actor runtime.
"""
from ._debug import (
Mk debugger tests work for arbitrary pre-REPL format Since this was changed as part of overall project wide logging format updates, and i ended up changing the both the crash and pause `.pdb()` msgs to include some multi-line-ascii-"stuff", might as well make the pre-prompt checks in the test suite more flexible to match. As such, this exposes 2 new constants inside the `.devx._debug` mod: - `._pause_msg: str` for the pre `tractor.pause()` header emitted via `log.pdb()` and, - `._crash_msg: str` for the pre `._post_mortem()` equiv when handling errors in debug mode. Adjust the test suite to use these values and thus make us more capable to absorb changes in the future as well: - add a new `in_prompt_msg()` predicate, very similar to `assert_before()` but minus `assert`s which takes in a `parts: list[str]` to match in the pre-prompt stdout. - delegate to `in_prompt_msg()` in `assert_before()` since it was mostly duplicate minus `assert`. - adjust all previous `<patt> in before` asserts to instead use `in_prompt_msg()` with separated pre-prompt-header vs. actor-name `parts`. - use new `._pause/crash_msg` values in all such calls including any `assert_before()` cases.
2024-03-05 16:43:23 +00:00
maybe_wait_for_debugger as maybe_wait_for_debugger,
acquire_debug_lock as acquire_debug_lock,
breakpoint as breakpoint,
pause as pause,
pause_from_sync as pause_from_sync,
Get multi-threaded sync-pausing fully workin! The final issue was making sure we do the same thing on ctl-c/SIGINT from the user. That is, if there's already a bg-thread in REPL, we `log.pdb()` about SIGINT shielding and re-draw the prompt; the same UX as normal actor-runtime-task behaviour. Reasons this wasn't workin.. and the fix: - `.pause_from_sync()` was overriding the local `repl` var with `None` delivered by (transitive) calls to `_pause(debug_func=None)`.. so remove all that and only assign it OAOO prior to thread-type case branching. - always call `DebugStatus.shield_sigint()` as needed from all requesting threads/tasks: - in `_pause_from_bg_root_thread()` BEFORE calling `._pause()` AND BEFORE yielding back to the bg-thread via `.started(out)` to ensure we're definitely overriding the handler in the `trio`-main-thread task before unblocking the requesting bg-thread. - from any requesting bg-thread in the root actor such that both its main-`trio`-thread scheduled task (as per above bullet) AND it are SIGINT shielded. - always call `.shield_sigint()` BEFORE any `greenback._await()` case don't entirely grok why yet, but it works)? - for `greenback._await()` case always set `bg_task` to the current one.. - tweaks to the `SIGINT` handler, now renamed `sigint_shield()` so as not to name-collide with the methods when editor-searching: - always try to `repr()` the REPL thread/task "owner" as well as the active `PdbREPL` instance. - add `.devx()` notes around the prompt flushing deats and comments for any root-actor-bg-thread edge cases. Related/supporting refinements: - add `get_lock()`/`get_debug_req()` factory funcs since the plan is to eventually implement both as `@singleton` instances per actor. - fix `acquire_debug_lock()`'s call-sig-bug for scheduling `request_root_stdio_lock()`.. - in `._pause()` only call `mk_pdb()` when `debug_func != None`. - add some todo/warning notes around the `cls.repl = None` in `DebugStatus.release()` `test_pause_from_sync()` tweaks: - don't use a `attach_patts.copy()`, since we always `break` on match. - do `pytest.fail()` on that ^ loop's fallthrough.. - pass `do_ctlc(child, patt=attach_key)` such that we always match the the current thread's name with the ctl-c triggered `.pdb()` emission. - oh yeah, return the last `before: str` from `do_ctlc()`. - in the script, flip `abandon_on_cancel=True` since when `False` it seems to cause `trio.run()` to hang on exit from the last bg-thread case?!?
2024-07-09 00:57:41 +00:00
sigint_shield as sigint_shield,
Mk debugger tests work for arbitrary pre-REPL format Since this was changed as part of overall project wide logging format updates, and i ended up changing the both the crash and pause `.pdb()` msgs to include some multi-line-ascii-"stuff", might as well make the pre-prompt checks in the test suite more flexible to match. As such, this exposes 2 new constants inside the `.devx._debug` mod: - `._pause_msg: str` for the pre `tractor.pause()` header emitted via `log.pdb()` and, - `._crash_msg: str` for the pre `._post_mortem()` equiv when handling errors in debug mode. Adjust the test suite to use these values and thus make us more capable to absorb changes in the future as well: - add a new `in_prompt_msg()` predicate, very similar to `assert_before()` but minus `assert`s which takes in a `parts: list[str]` to match in the pre-prompt stdout. - delegate to `in_prompt_msg()` in `assert_before()` since it was mostly duplicate minus `assert`. - adjust all previous `<patt> in before` asserts to instead use `in_prompt_msg()` with separated pre-prompt-header vs. actor-name `parts`. - use new `._pause/crash_msg` values in all such calls including any `assert_before()` cases.
2024-03-05 16:43:23 +00:00
open_crash_handler as open_crash_handler,
maybe_open_crash_handler as maybe_open_crash_handler,
Further formalize `greenback` integration Since we more or less require it for `tractor.pause_from_sync()` this refines enable toggles and their relay down the actor tree as well as more explicit logging around init and activation. Tweaks summary: - `.info()` report the module if discovered during root boot. - use a `._state._runtime_vars['use_greenback']: bool` activation flag inside `Actor._from_parent()` to determine if the sub should try to use it and set to `False` if mod-loading fails / not installed. - expose `maybe_init_greenback()` from `.devx` sugpkg. - comment out RTE in `._pause()` for now since we already have it in `.pause_from_sync()`. - always `.exception()` on `maybe_init_greenback()` import errors to clarify the underlying failure deats. - always explicitly report if `._state._runtime_vars['use_greenback']` was NOT set when `.pause_from_sync()` is called. Other `._runtime.async_main()` adjustments: - combine the "internal error call ur parents" message and the failed registry contact status into one new `err_report: str`. - drop the final exception handler's call to `Actor.lifetime_stack.close()` since we're already doing it in the `finally:` block and the earlier call has no currently known benefit. - only report on the `.lifetime_stack()` callbacks if any are detected as registered.
2024-06-28 18:25:53 +00:00
maybe_init_greenback as maybe_init_greenback,
Mk debugger tests work for arbitrary pre-REPL format Since this was changed as part of overall project wide logging format updates, and i ended up changing the both the crash and pause `.pdb()` msgs to include some multi-line-ascii-"stuff", might as well make the pre-prompt checks in the test suite more flexible to match. As such, this exposes 2 new constants inside the `.devx._debug` mod: - `._pause_msg: str` for the pre `tractor.pause()` header emitted via `log.pdb()` and, - `._crash_msg: str` for the pre `._post_mortem()` equiv when handling errors in debug mode. Adjust the test suite to use these values and thus make us more capable to absorb changes in the future as well: - add a new `in_prompt_msg()` predicate, very similar to `assert_before()` but minus `assert`s which takes in a `parts: list[str]` to match in the pre-prompt stdout. - delegate to `in_prompt_msg()` in `assert_before()` since it was mostly duplicate minus `assert`. - adjust all previous `<patt> in before` asserts to instead use `in_prompt_msg()` with separated pre-prompt-header vs. actor-name `parts`. - use new `._pause/crash_msg` values in all such calls including any `assert_before()` cases.
2024-03-05 16:43:23 +00:00
post_mortem as post_mortem,
Big debugger rework, more tolerance for internal err-hangs Since i was running into them (internal errors) during lock request machinery dev and was getting all sorts of difficult to understand hangs whenever i intro-ed a bug to either side of the ipc ctx; this all while trying to get the msg-spec working for `Lock` requesting subactors.. Deats: - hideframes for `@acm`s and `trio.Event.wait()`, `Lock.release()`. - better detail out the `Lock.acquire/release()` impls - drop `Lock.remote_task_in_debug`, use new `.ctx_in_debug`. - add a `Lock.release(force: bool)`. - move most of what was `_acquire_debug_lock_from_root_task()` and some of the `lock_tty_for_child().__a[enter/exit]()` logic into `Lock.[acquire/release]()` including bunch more logging. - move `lock_tty_for_child()` up in the module to below `Lock`, with some rework: - drop `subactor_uid: tuple` arg since we can just use the `ctx`.. - add exception handler blocks for reporting internal (impl) errors and always force release the lock in such cases. - extend `DebugStatus` (prolly will rename to `DebugRequest` btw): - add `.req_ctx: Context` for subactor side. - add `.req_finished: trio.Event` to sub to signal request task exit. - extend `.shield_sigint()` doc-str. - add `.release()` to encaps all the state mgmt previously strewn about inside `._pause()`.. - use new `DebugStatus.release()` to replace all the duplication: - inside `PdbREPL.set_[continue/quit]()`. - inside `._pause()` for the subactor branch on internal repl-invocation error cases, - in the `_enter_repl_sync()` closure on error, - replace `apply_debug_codec()` -> `apply_debug_pldec()` in tandem with the new `PldRx` sub-sys which handles the new `__pld_spec__`. - add a new `pformat_cs()` helper orig to help debug cs stack a corruption; going to move to `.devx.pformat` obvi. - rename `wait_for_parent_stdin_hijack()` -> `request_root_stdio_lock()` with improvements: - better doc-str and add todos, - use `DebugStatus` more stringently to encaps all subactor req state. - error handling blocks for cancellation and straight up impl errors directly around the `.open_context()` block with the latter doing a `ctx.cancel()` to avoid hanging in the shielded `.req_cs` scope. - similar exc blocks for the func's overall body with explicit `log.exception()` reporting. - only set the new `DebugStatus.req_finished: trio.Event` in `finally`. - rename `mk_mpdb()` -> `mk_pdb()` and don't cal `.shield_sigint()` implicitly since the caller usage does matter for this. - factor out `any_connected_locker_child()` from the SIGINT handler. - rework SIGINT handler to better handle any stale-lock/hang cases: - use new `Lock.ctx_in_debug: Context` to detect subactor-in-debug. and use it to cancel any lock request instead of the lower level - use `problem: str` summary approach to log emissions. - rework `_pause()` given all of the above, stuff not yet mentioned: - don't take `shield: bool` input and proxy to `debug_func()` (for now). - drop `extra_frames_up_when_async: int` usage, expect `**debug_func_kwargs` to passthrough an `api_frame: Frametype` (more on this later). - lotsa asserts around the request ctx vs. task-in-debug ctx using new `current_ipc_ctx()`. - asserts around `DebugStatus` state. - rework and simplify the `debug_func` hooks, `_set_trace()`/`_post_mortem()`: - make them accept a non-optional `repl: PdbRepl` and `api_frame: FrameType` which should be used to set the current frame when the REPL engages. - always hide the hook frames. - always accept a `tb: TracebackType` to `_post_mortem()`. |_ copy and re-impl what was the delegation to `pdbp.xpm()`/`pdbp.post_mortem()` and instead call the underlying `Pdb.interaction()` ourselves with a `caller_frame` and tb instance. - adjust the public `.pause()` impl: - accept optional `hide_tb` and `api_frame` inputs. - mask opening a cancel-scope for now (can cause `trio` stack corruption, see notes) and thus don't use the `shield` input other then to eventually passthrough to `_post_mortem()`? |_ thus drop `task_status` support for now as well. |_ pretty sure correct soln is a debug-nursery around `._invoke()`. - since no longer using `extra_frames_up_when_async` inside `debug_func()`s ensure all public apis pass a `api_frame`. - re-impl our `tractor.post_mortem()` to directly call into `._pause()` instead of binding in via `partial` and mk it take similar input as `.pause()`. - drop `Lock.release()` from `_maybe_enter_pm()`, expose and pass expected frame and tb. - use necessary changes from all the above within `maybe_wait_for_debugger()` and `acquire_debug_lock()`. Lel, sorry thought that would be shorter.. There's still a lot more re-org to do particularly with `DebugStatus` encapsulation but it's coming in follow up.
2024-05-08 13:08:01 +00:00
mk_pdb as mk_pdb,
Kick off `.devx` subpkg for our dev tools B) Where `.devx` is "developer experience", a hopefully broad enough subpkg name for all the slick stuff planned to augment working on the actor runtime :boom: Move the `._debug` module into the new subpkg and adjust rest of core code base to reflect import path change. Also add a new `.devx._debug.open_crash_handler()` manager for wrapping any sync code outside a `trio.run()` which is handy for eventual CLI addons for popular frameworks like `click`/`typer`.
2023-09-28 18:14:50 +00:00
)
Add `stackscope` tree pprinter triggered by SIGUSR1 Can be optionally enabled via a new `enable_stack_on_sig()` which will swap in the SIGUSR1 handler. Much thanks to @oremanj for writing this amazing project, it's thus far helped me fix some very subtle hangs inside our new IPC-context cancellation machinery that would have otherwise taken much more manual pdb-ing and hair pulling XD Full credit for `dump_task_tree()` goes to the original project author with some minor tweaks as was handed to me via the trio-general matrix room B) Slight changes from orig version: - use a `log.pdb()` emission to pprint to console - toss in an ex sh CLI cmd to trigger the dump from another terminal using `kill` + `pgrep`.
2024-02-20 13:59:21 +00:00
from ._stackscope import (
enable_stack_on_sig as enable_stack_on_sig,
)
Big debugger rework, more tolerance for internal err-hangs Since i was running into them (internal errors) during lock request machinery dev and was getting all sorts of difficult to understand hangs whenever i intro-ed a bug to either side of the ipc ctx; this all while trying to get the msg-spec working for `Lock` requesting subactors.. Deats: - hideframes for `@acm`s and `trio.Event.wait()`, `Lock.release()`. - better detail out the `Lock.acquire/release()` impls - drop `Lock.remote_task_in_debug`, use new `.ctx_in_debug`. - add a `Lock.release(force: bool)`. - move most of what was `_acquire_debug_lock_from_root_task()` and some of the `lock_tty_for_child().__a[enter/exit]()` logic into `Lock.[acquire/release]()` including bunch more logging. - move `lock_tty_for_child()` up in the module to below `Lock`, with some rework: - drop `subactor_uid: tuple` arg since we can just use the `ctx`.. - add exception handler blocks for reporting internal (impl) errors and always force release the lock in such cases. - extend `DebugStatus` (prolly will rename to `DebugRequest` btw): - add `.req_ctx: Context` for subactor side. - add `.req_finished: trio.Event` to sub to signal request task exit. - extend `.shield_sigint()` doc-str. - add `.release()` to encaps all the state mgmt previously strewn about inside `._pause()`.. - use new `DebugStatus.release()` to replace all the duplication: - inside `PdbREPL.set_[continue/quit]()`. - inside `._pause()` for the subactor branch on internal repl-invocation error cases, - in the `_enter_repl_sync()` closure on error, - replace `apply_debug_codec()` -> `apply_debug_pldec()` in tandem with the new `PldRx` sub-sys which handles the new `__pld_spec__`. - add a new `pformat_cs()` helper orig to help debug cs stack a corruption; going to move to `.devx.pformat` obvi. - rename `wait_for_parent_stdin_hijack()` -> `request_root_stdio_lock()` with improvements: - better doc-str and add todos, - use `DebugStatus` more stringently to encaps all subactor req state. - error handling blocks for cancellation and straight up impl errors directly around the `.open_context()` block with the latter doing a `ctx.cancel()` to avoid hanging in the shielded `.req_cs` scope. - similar exc blocks for the func's overall body with explicit `log.exception()` reporting. - only set the new `DebugStatus.req_finished: trio.Event` in `finally`. - rename `mk_mpdb()` -> `mk_pdb()` and don't cal `.shield_sigint()` implicitly since the caller usage does matter for this. - factor out `any_connected_locker_child()` from the SIGINT handler. - rework SIGINT handler to better handle any stale-lock/hang cases: - use new `Lock.ctx_in_debug: Context` to detect subactor-in-debug. and use it to cancel any lock request instead of the lower level - use `problem: str` summary approach to log emissions. - rework `_pause()` given all of the above, stuff not yet mentioned: - don't take `shield: bool` input and proxy to `debug_func()` (for now). - drop `extra_frames_up_when_async: int` usage, expect `**debug_func_kwargs` to passthrough an `api_frame: Frametype` (more on this later). - lotsa asserts around the request ctx vs. task-in-debug ctx using new `current_ipc_ctx()`. - asserts around `DebugStatus` state. - rework and simplify the `debug_func` hooks, `_set_trace()`/`_post_mortem()`: - make them accept a non-optional `repl: PdbRepl` and `api_frame: FrameType` which should be used to set the current frame when the REPL engages. - always hide the hook frames. - always accept a `tb: TracebackType` to `_post_mortem()`. |_ copy and re-impl what was the delegation to `pdbp.xpm()`/`pdbp.post_mortem()` and instead call the underlying `Pdb.interaction()` ourselves with a `caller_frame` and tb instance. - adjust the public `.pause()` impl: - accept optional `hide_tb` and `api_frame` inputs. - mask opening a cancel-scope for now (can cause `trio` stack corruption, see notes) and thus don't use the `shield` input other then to eventually passthrough to `_post_mortem()`? |_ thus drop `task_status` support for now as well. |_ pretty sure correct soln is a debug-nursery around `._invoke()`. - since no longer using `extra_frames_up_when_async` inside `debug_func()`s ensure all public apis pass a `api_frame`. - re-impl our `tractor.post_mortem()` to directly call into `._pause()` instead of binding in via `partial` and mk it take similar input as `.pause()`. - drop `Lock.release()` from `_maybe_enter_pm()`, expose and pass expected frame and tb. - use necessary changes from all the above within `maybe_wait_for_debugger()` and `acquire_debug_lock()`. Lel, sorry thought that would be shorter.. There's still a lot more re-org to do particularly with `DebugStatus` encapsulation but it's coming in follow up.
2024-05-08 13:08:01 +00:00
from .pformat import (
add_div as add_div,
pformat_caller_frame as pformat_caller_frame,
pformat_boxed_tb as pformat_boxed_tb,
)
Handle cpython builds with `libedit` for `readline` Since `uv`'s cpython distributions are built this way `pdbp`'s tab completion was breaking (as was vi-mode). This adds a new `.devx._enable_readline_feats()` import hook which checks for the appropriate library and applies settings accordingly.
2025-02-25 15:18:31 +00:00
Big debugger rework, more tolerance for internal err-hangs Since i was running into them (internal errors) during lock request machinery dev and was getting all sorts of difficult to understand hangs whenever i intro-ed a bug to either side of the ipc ctx; this all while trying to get the msg-spec working for `Lock` requesting subactors.. Deats: - hideframes for `@acm`s and `trio.Event.wait()`, `Lock.release()`. - better detail out the `Lock.acquire/release()` impls - drop `Lock.remote_task_in_debug`, use new `.ctx_in_debug`. - add a `Lock.release(force: bool)`. - move most of what was `_acquire_debug_lock_from_root_task()` and some of the `lock_tty_for_child().__a[enter/exit]()` logic into `Lock.[acquire/release]()` including bunch more logging. - move `lock_tty_for_child()` up in the module to below `Lock`, with some rework: - drop `subactor_uid: tuple` arg since we can just use the `ctx`.. - add exception handler blocks for reporting internal (impl) errors and always force release the lock in such cases. - extend `DebugStatus` (prolly will rename to `DebugRequest` btw): - add `.req_ctx: Context` for subactor side. - add `.req_finished: trio.Event` to sub to signal request task exit. - extend `.shield_sigint()` doc-str. - add `.release()` to encaps all the state mgmt previously strewn about inside `._pause()`.. - use new `DebugStatus.release()` to replace all the duplication: - inside `PdbREPL.set_[continue/quit]()`. - inside `._pause()` for the subactor branch on internal repl-invocation error cases, - in the `_enter_repl_sync()` closure on error, - replace `apply_debug_codec()` -> `apply_debug_pldec()` in tandem with the new `PldRx` sub-sys which handles the new `__pld_spec__`. - add a new `pformat_cs()` helper orig to help debug cs stack a corruption; going to move to `.devx.pformat` obvi. - rename `wait_for_parent_stdin_hijack()` -> `request_root_stdio_lock()` with improvements: - better doc-str and add todos, - use `DebugStatus` more stringently to encaps all subactor req state. - error handling blocks for cancellation and straight up impl errors directly around the `.open_context()` block with the latter doing a `ctx.cancel()` to avoid hanging in the shielded `.req_cs` scope. - similar exc blocks for the func's overall body with explicit `log.exception()` reporting. - only set the new `DebugStatus.req_finished: trio.Event` in `finally`. - rename `mk_mpdb()` -> `mk_pdb()` and don't cal `.shield_sigint()` implicitly since the caller usage does matter for this. - factor out `any_connected_locker_child()` from the SIGINT handler. - rework SIGINT handler to better handle any stale-lock/hang cases: - use new `Lock.ctx_in_debug: Context` to detect subactor-in-debug. and use it to cancel any lock request instead of the lower level - use `problem: str` summary approach to log emissions. - rework `_pause()` given all of the above, stuff not yet mentioned: - don't take `shield: bool` input and proxy to `debug_func()` (for now). - drop `extra_frames_up_when_async: int` usage, expect `**debug_func_kwargs` to passthrough an `api_frame: Frametype` (more on this later). - lotsa asserts around the request ctx vs. task-in-debug ctx using new `current_ipc_ctx()`. - asserts around `DebugStatus` state. - rework and simplify the `debug_func` hooks, `_set_trace()`/`_post_mortem()`: - make them accept a non-optional `repl: PdbRepl` and `api_frame: FrameType` which should be used to set the current frame when the REPL engages. - always hide the hook frames. - always accept a `tb: TracebackType` to `_post_mortem()`. |_ copy and re-impl what was the delegation to `pdbp.xpm()`/`pdbp.post_mortem()` and instead call the underlying `Pdb.interaction()` ourselves with a `caller_frame` and tb instance. - adjust the public `.pause()` impl: - accept optional `hide_tb` and `api_frame` inputs. - mask opening a cancel-scope for now (can cause `trio` stack corruption, see notes) and thus don't use the `shield` input other then to eventually passthrough to `_post_mortem()`? |_ thus drop `task_status` support for now as well. |_ pretty sure correct soln is a debug-nursery around `._invoke()`. - since no longer using `extra_frames_up_when_async` inside `debug_func()`s ensure all public apis pass a `api_frame`. - re-impl our `tractor.post_mortem()` to directly call into `._pause()` instead of binding in via `partial` and mk it take similar input as `.pause()`. - drop `Lock.release()` from `_maybe_enter_pm()`, expose and pass expected frame and tb. - use necessary changes from all the above within `maybe_wait_for_debugger()` and `acquire_debug_lock()`. Lel, sorry thought that would be shorter.. There's still a lot more re-org to do particularly with `DebugStatus` encapsulation but it's coming in follow up.
2024-05-08 13:08:01 +00:00
# TODO, move this to a new `.devx._pdbp` mod?
Handle cpython builds with `libedit` for `readline` Since `uv`'s cpython distributions are built this way `pdbp`'s tab completion was breaking (as was vi-mode). This adds a new `.devx._enable_readline_feats()` import hook which checks for the appropriate library and applies settings accordingly.
2025-02-25 15:18:31 +00:00
def _enable_readline_feats() -> str:
'''
Handle `readline` when compiled with `libedit` to avoid breaking
tab completion in `pdbp` (and its dep `tabcompleter`)
particularly since `uv` cpython distis are compiled this way..
See docs for deats,
https://docs.python.org/3/library/readline.html#module-readline
Originally discovered soln via SO answer,
https://stackoverflow.com/q/49287102
'''
import readline
if (
# 3.13+ attr
# https://docs.python.org/3/library/readline.html#readline.backend
(getattr(readline, 'backend', False) == 'libedit')
or
'libedit' in readline.__doc__
):
readline.parse_and_bind("python:bind -v")
readline.parse_and_bind("python:bind ^I rl_complete")
return 'libedit'
else:
readline.parse_and_bind("tab: complete")
readline.parse_and_bind("set editing-mode vi")
readline.parse_and_bind("set keymap vi")
return 'readline'
_enable_readline_feats()