1/* Part of SWI-Prolog 2 3 Author: Jan Wielemaker 4 E-mail: jan@swi-prolog.org 5 WWW: http://www.swi-prolog.org 6 Copyright (c) 2023-2024, SWI-Prolog Solutions b.v. 7 All rights reserved. 8 9 Redistribution and use in source and binary forms, with or without 10 modification, are permitted provided that the following conditions 11 are met: 12 13 1. Redistributions of source code must retain the above copyright 14 notice, this list of conditions and the following disclaimer. 15 16 2. Redistributions in binary form must reproduce the above copyright 17 notice, this list of conditions and the following disclaimer in 18 the documentation and/or other materials provided with the 19 distribution. 20 21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 29 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 31 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 POSSIBILITY OF SUCH DAMAGE. 33*/ 34 35:- module(janus, 36 [ py_version/0, 37 38 py_call/1, % +Call 39 py_call/2, % +Call, -Return 40 py_call/3, % +Call, -Return, +Options 41 py_iter/2, % +Call, -Return 42 py_iter/3, % +Call, -Return, +Options 43 py_setattr/3, % +On, +Name, +Value 44 py_free/1, % +Obj 45 py_is_object/1, % @Term 46 py_is_dict/1, % @Term 47 py_with_gil/1, % :Goal 48 py_gil_owner/1, % -ThreadID 49 50 py_func/3, % +Module, +Func, -Return 51 py_func/4, % +Module, +Func, -Return, +Options 52 py_dot/3, % +ObjRef, +Meth, ?Ret 53 py_dot/4, % +ObjRef, +Meth, -Ret, +Options 54 55 values/3, % +Dict, +Path, ?Val 56 keys/2, % +Dict, ?Keys 57 key/2, % +Dict, ?Key 58 items/2, % +Dict, ?Items 59 60 py_shell/0, 61 62 py_pp/1, % +Term 63 py_pp/2, % +Stream, +Term 64 py_pp/3, % +Stream, +Term, +Options 65 66 py_object_dir/2, % +ObjRef, -List 67 py_object_dict/2, % +ObjRef, -Dict 68 py_obj_dir/2, % +ObjRef, -List (deprecated) 69 py_obj_dict/2, % +ObjRef, -Dict (deprecated) 70 py_type/2, % +ObjRef, -Type:atom 71 py_isinstance/2, % +ObjRef, +Type 72 py_module_exists/1, % +Module 73 py_hasattr/2, % +Module, ?Symbol 74 75 py_import/2, % +Spec, +Options 76 py_module/2, % +Module:atom, +Source:string 77 78 py_initialize/3, % +Program, +Argv, +Options 79 py_lib_dirs/1, % -Dirs 80 py_add_lib_dir/1, % +Dir 81 py_add_lib_dir/2, % +Dir,+Where 82 83 op(200, fy, @), % @constant 84 op(50, fx, #) % #Value 85 ]). 86:- meta_predicate py_with_gil(). 87 88:- use_module(library(apply_macros), []). 89:- autoload(library(lists), [append/3, member/2, append/2, last/2]). 90:- autoload(library(apply), 91 [maplist/2, exclude/3, maplist/3, convlist/3, partition/4]). 92:- autoload(library(error), [must_be/2, domain_error/2]). 93:- autoload(library(dicts), [dict_keys/2]). 94:- autoload(library(option), [dict_options/2, select_option/4, option/2]). 95:- autoload(library(prolog_code), [comma_list/2]). 96:- autoload(library(readutil), [read_line_to_string/2, read_file_to_string/3]). 97:- autoload(library(wfs), [call_delays/2, delays_residual_program/2]). 98:- autoload(library(dcg/high_order), [sequence//2, sequence//3]). 99 100:- if(\+current_predicate(py_call/1)). 101:- if(current_prolog_flag(windows, true)). 102:- use_module(library(shlib), [win_add_dll_directory/1]). 103 104% Just having the Python dir in PATH seems insufficient. We also need to 105% add the directory to the DLL search path. 106add_python_dll_dir :- 107 ( current_prolog_flag(msys2, true) 108 -> absolute_file_name(path('libpython3.dll'), DLL, [access(read)]) 109 ; absolute_file_name(path('python3.dll'), DLL, [access(read)]) 110 ), 111 file_directory_name(DLL, Dir), 112 win_add_dll_directory(Dir). 113:- initialization(add_python_dll_dir, now). 114:- endif. 115 116:- use_foreign_library(foreign(janus), [visibility(global)]). 117:- endif. 118 119:- predicate_options(py_call/3, 3, 120 [ py_object(boolean), 121 py_string_as(oneof([string,atom])) 122 ]). 123:- predicate_options(py_func/4, 4, 124 [ pass_to(py_call/3, 3) 125 ]). 126:- predicate_options(py_dot/5, 5, 127 [ pass_to(py_call/3, 3) 128 ]). 129 130:- public 131 py_initialize/0, 132 py_call_string/3, 133 py_write/2, 134 py_readline/4. 135 136:- create_prolog_flag(py_backtrace, true, [type(boolean), keep(true)]). 137:- create_prolog_flag(py_backtrace_depth, 4, [type(integer), keep(true)]). 138:- create_prolog_flag(py_argv, [], [type(term), keep(true)]). 139 140/** <module> Call Python from Prolog 141 142This library implements calling Python from Prolog. It is available 143directly from Prolog if the janus package is bundled. The library 144provides access to an _embedded_ Python instance. If SWI-Prolog is 145embedded into Python using the Python package ``janus-swi``, this 146library is provided either from Prolog or from the Python package. 147 148Normally, the Prolog user can simply start calling Python using 149py_call/2 or friends. In special cases it may be needed to initialize 150Python with options using py_initialize/3 and optionally the Python 151search path may be extended using py_add_lib_dir/1. 152*/ 153 154%! py_version is det. 155% 156% Print version info on the embedded Python installation based on 157% Python `sys.version`. If a Python _virtual environment_ (venv) is 158% active, indicate this with the location of this environment found. 159 160py_version :- 161 py_call(sys:version, PythonVersion), 162 py_call(janus_swi:version_str(), JanusVersion), 163 print_message(information, janus(version(JanusVersion, PythonVersion))), 164 ( py_venv(VEnvDir, EnvSiteDir) 165 -> print_message(information, janus(venv(VEnvDir, EnvSiteDir))) 166 ; true 167 ). 168 169 170%! py_call(+Call) is det. 171%! py_call(+Call, -Return) is det. 172%! py_call(+Call, -Return, +Options) is det. 173% 174% Call Python and return the result of the called function. Call has 175% the shape `[Target][:Action]*`, where `Target` is either a Python 176% module name or a Python object reference. Each `Action` is either an 177% atom to get the denoted attribute from current `Target` or it is a 178% compound term where the first argument is the function or method 179% name and the arguments provide the parameters to the Python 180% function. On success, the returned Python object is translated to 181% Prolog. `Action` without a `Target` denotes a buit-in function. 182% 183% Arguments to Python functions use the Python conventions. Both 184% _positional_ and _keyword_ arguments are supported. Keyword 185% arguments are written as `Name = Value` and must appear after the 186% positional arguments. 187% 188% Below are some examples. 189% 190% % call a built-in 191% ?- py_call(print("Hello World!\n")). 192% true. 193% 194% % call a built-in (alternative) 195% ?- py_call(builtins:print("Hello World!\n")). 196% true. 197% 198% % call function in a module 199% ?- py_call(sys:getsizeof([1,2,3]), Size). 200% Size = 80. 201% 202% % call function on an attribute of a module 203% ?- py_call(sys:path:append("/home/bob/janus")). 204% true 205% 206% % get attribute from a module 207% ?- py_call(sys:path, Path) 208% Path = ["dir1", "dir2", ...] 209% 210% Given a class in a file `dog.py` such as the following example from 211% the Python documentation 212% 213% ``` 214% class Dog: 215% tricks = [] 216% 217% def __init__(self, name): 218% self.name = name 219% 220% def add_trick(self, trick): 221% self.tricks.append(trick) 222% ``` 223% 224% We can interact with this class as below. Note that ``$Doc`` in the 225% SWI-Prolog toplevel refers to the last toplevel binding for the 226% variable `Dog`. 227% 228% ?- py_call(dog:'Dog'("Fido"), Dog). 229% Dog = <py_Dog>(0x7f095c9d02e0). 230% 231% ?- py_call($Dog:add_trick("roll_over")). 232% Dog = <py_Dog>(0x7f095c9d02e0). 233% 234% ?- py_call($Dog:tricks, Tricks). 235% Dog = <py_Dog>(0x7f095c9d02e0), 236% Tricks = ["roll_over"] 237% 238% If the principal term of the first argument is not `Target:Func`, 239% The argument is evaluated as the initial target, i.e., it must be an 240% object reference or a module. For example: 241% 242% ?- py_call(dog:'Dog'("Fido"), Dog), 243% py_call(Dog, X). 244% Dog = X, X = <py_Dog>(0x7fa8cbd12050). 245% ?- py_call(sys, S). 246% S = <py_module>(0x7fa8cd582390). 247% 248% Options processed: 249% 250% - py_object(Boolean) 251% If `true` (default `false`), translate the return as a Python 252% object reference. Some objects are _always_ translated to 253% Prolog, regardless of this flag. These are the Python constants 254% ``None``, ``True`` and ``False`` as well as instances of the 255% Python base classes `int`, `float`, `str` or `tuple`. Instances 256% of sub classes of these base classes are controlled by this 257% option. 258% - py_string_as(+Type) 259% If Type is `atom` (default), translate a Python String into a 260% Prolog atom. If Type is `string`, translate into a Prolog string. 261% Strings are more efficient if they are short lived. 262% - py_dict_as(+Type) 263% One of `dict` (default) to map a Python dict to a SWI-Prolog 264% dict if all keys can be represented. If `{}` or not all keys 265% can be represented, Return is unified to a term `{k:v, ...}` 266% or `py({})` if the Python dict is empty. 267% 268% @compat PIP. The options `py_string_as` and `py_dict_as` are 269% SWI-Prolog specific, where SWI-Prolog Janus represents Python 270% strings as atoms as required by the PIP and it represents Python 271% dicts by default as SWI-Prolog dicts. The predicates values/3, 272% keys/2, etc. provide portable access to the data in the dict. 273 274%! py_iter(+Iterator, -Value) is nondet. 275%! py_iter(+Iterator, -Value, +Options) is nondet. 276% 277% True when Value is returned by the Python Iterator. Python iterators 278% may be used to implement non-deterministic foreign predicates. The 279% implementation uses these steps: 280% 281% 1. Evaluate Iterator as py_call/2 evaluates its first argument, 282% except the ``Obj:Attr = Value`` construct is not accepted. 283% 2. Call ``__iter__`` on the result to get the iterator itself. 284% 3. Get the ``__next__`` function of the iterator. 285% 4. Loop over the return values of the _next_ function. If 286% the Python return value unifies with Value, succeed with 287% a choicepoint. Abort on Python or unification exceptions. 288% 5. Re-satisfaction continues at (4). 289% 290% The example below uses the built-in iterator range(): 291% 292% ?- py_iter(range(1,3), X). 293% X = 1 ; 294% X = 2. 295% 296% Note that the implementation performs a _look ahead_, i.e., after 297% successful unification it calls `__next__()` again. On failure the 298% Prolog predicate succeeds deterministically. On success, the next 299% candidate is stored. 300% 301% Note that a Python _generator_ is a Python _iterator_. Therefore, 302% given the Python generator expression below, we can use 303% py_iter(squares(1,5),X) to generate the squares on backtracking. 304% 305% ``` 306% def squares(start, stop): 307% for i in range(start, stop): 308% yield i * i 309% ``` 310% 311% @arg Options is processed as with py_call/3. 312% @bug Iterator may not depend on janus.query(), i.e., it is not 313% possible to iterate over a Python iterator that under the hoods 314% relies on a Prolog non-deterministic predicate. 315% @compat PIP. The same remarks as for py_call/2 apply. 316 317%! py_setattr(+Target, +Name, +Value) is det. 318% 319% Set a Python attribute on an object. If Target is an atom, it is 320% interpreted as a module. Otherwise it is normally an object 321% reference. py_setattr/3 allows for _chaining_ and behaves as if 322% defined as 323% 324% py_setattr(Target, Name, Value) :- 325% py_call(Target, Obj, [py_object(true)]), 326% py_call(setattr(Obj, Name, Value)). 327% 328% @compat PIP 329 330%! py_run(+String, +Globals, +Locals, -Result, +Options) is det. 331% 332% Interface to Py_CompileString() followed by PyEval_EvalCode(). 333% Options: 334% 335% - file_name(String) 336% Errors are reported against this pseudo file name 337% - start(Token) 338% One of `eval`, `file` (default) or `single`. 339% 340% @arg Globals is a dict 341% @arg Locals is a dict 342 343%! py_is_object(@Term) is semidet. 344% 345% True when Term is a Python object reference. Fails silently if Term 346% is any other Prolog term. 347% 348% @error existence_error(py_object, Term) is raised of Term is a 349% Python object, but it has been freed using py_free/1. 350% 351% @compat PIP. The SWI-Prolog implementation is safe in the sense that 352% an arbitrary term cannot be confused with a Python object and a 353% reliable error is generated if the references has been freed. 354% Portable applications can not rely on this. 355 356%! py_is_dict(@Term) is semidet. 357% 358% True if Term is a Prolog term that represents a Python dict. 359% 360% @compat PIP. The SWI-Prolog version accepts both a SWI-Prolog dict 361% and the `{k:v,...}` representation. See `py_dict_as` option of 362% py_call/2. 363 364py_is_dict(Dict), is_dict(Dict) => true. 365py_is_dict(py({})) => true. 366py_is_dict(py({KV})) => is_kv(KV). 367py_is_dict({KV}) => is_kv(KV). 368 369is_kv((K:V,T)) => ground(K), ground(V), is_kv(T). 370is_kv(K:V) => ground(K), ground(V). 371 372 373%! py_free(+Obj) is det. 374% 375% Immediately free (decrement the reference count) for the Python 376% object Obj. Further reference to Obj using e.g., py_call/2 or 377% py_free/1 raises an `existence_error`. Note that by decrementing the 378% reference count, we make the reference invalid from Prolog. This may 379% not actually delete the object because the object may have 380% references inside Python. 381% 382% Prolog references to Python objects are subject to atom garbage 383% collection and thus normally do not need to be freed explicitly. 384% 385% @compat PIP. The SWI-Prolog implementation is safe and normally 386% reclaiming Python object can be left to the garbage collector. 387% Portable applications may not assume garbage collection of Python 388% objects and must ensure to call py_free/1 exactly once on any Python 389% object reference. Not calling py_free/1 leaks the Python object. 390% Calling it twice may lead to undefined behavior. 391 392%! py_with_gil(:Goal) is semidet. 393% 394% Run Goal as once(Goal) while holding the Phyton GIL (_Global 395% Interpreter Lock_). Note that all predicates that interact with 396% Python lock the GIL. This predicate is only required if we wish to 397% make multiple calls to Python while keeping the GIL. The GIL is a 398% _recursive_ lock and thus calling py_call/1,2 while holding the GIL 399% does not _deadlock_. 400 401%! py_gil_owner(-Thread) is semidet. 402% 403% True when the Python GIL is owned by Thread. Note that, unless 404% Thread is the calling thread, this merely samples the current 405% state and may thus no longer be true when the predicate succeeds. 406% This predicate is intended to help diagnose _deadlock_ problems. 407% 408% Note that this predicate returns the Prolog threads that locked 409% the GIL. It is however possible that Python releases the GIL, for 410% example if it performs a blocking call. In this scenario, some 411% other thread or no thread may hold the gil. 412 413 414 /******************************* 415 * COMPATIBILIY * 416 *******************************/ 417 418%! py_func(+Module, +Function, -Return) is det. 419%! py_func(+Module, +Function, -Return, +Options) is det. 420% 421% Call Python Function in Module. The SWI-Prolog implementation is 422% equivalent to py_call(Module:Function, Return). See py_call/2 for 423% details. 424% 425% @compat PIP. See py_call/2 for notes. Note that, as this 426% implementation is based on py_call/2, Function can use _chaining_, 427% e.g., py_func(sys, path:append(dir), Return) is accepted by this 428% implementation, but not portable. 429 430py_func(Module, Function, Return) :- 431 py_call(Module:Function, Return). 432py_func(Module, Function, Return, Options) :- 433 py_call(Module:Function, Return, Options). 434 435%! py_dot(+ObjRef, +MethAttr, -Ret) is det. 436%! py_dot(+ObjRef, +MethAttr, -Ret, +Options) is det. 437% 438% Call a method or access an attribute on the object ObjRef. The 439% SWI-Prolog implementation is equivalent to py_call(ObjRef:MethAttr, 440% Return). See py_call/2 for details. 441% 442% @compat PIP. See py_func/3 for details. 443 444py_dot(ObjRef, MethAttr, Ret) :- 445 py_call(ObjRef:MethAttr, Ret). 446py_dot(ObjRef, MethAttr, Ret, Options) :- 447 py_call(ObjRef:MethAttr, Ret, Options). 448 449 450 /******************************* 451 * PORTABLE ACCESS TO DICTS * 452 *******************************/ 453 454%! values(+Dict, +Path, ?Val) is semidet. 455% 456% Get the value associated with Dict at Path. Path is either a single 457% key or a list of keys. 458% 459% @compat PIP. Note that this predicate handle a SWI-Prolog dict, a 460% {k:v, ...} term as well as py({k:v, ...}. 461 462values(Dict, Key, Val), is_dict(Dict), atom(Key) => 463 get_dict(Key, Dict, Val). 464values(Dict, Keys, Val), is_dict(Dict), is_list(Keys) => 465 get_dict_path(Keys, Dict, Val). 466values(py({CommaDict}), Key, Val) => 467 comma_values(CommaDict, Key, Val). 468values({CommaDict}, Key, Val) => 469 comma_values(CommaDict, Key, Val). 470 471get_dict_path([], Val, Val). 472get_dict_path([H|T], Dict, Val) :- 473 get_dict(H, Dict, Val0), 474 get_dict_path(T, Val0, Val). 475 476comma_values(CommaDict, Key, Val), atom(Key) => 477 comma_value(Key, CommaDict, Val). 478comma_values(CommaDict, Keys, Val), is_list(Keys) => 479 comma_value_path(Keys, CommaDict, Val). 480 481comma_value(Key, Key:Val0, Val) => 482 Val = Val0. 483comma_value(Key, (_,Tail), Val) => 484 comma_value(Key, Tail, Val). 485 486comma_value_path([], Val, Val). 487comma_value_path([H|T], Dict, Val) :- 488 comma_value(H, Dict, Val0), 489 comma_value_path(T, Val0, Val). 490 491%! keys(+Dict, ?Keys) is det. 492% 493% True when Keys is a list of keys that appear in Dict. 494% 495% @compat PIP. Note that this predicate handle a SWI-Prolog dict, a 496% {k:v, ...} term as well as py({k:v, ...}. 497 498keys(Dict, Keys), is_dict(Dict) => 499 dict_keys(Dict, Keys). 500keys(py({CommaDict}), Keys) => 501 comma_dict_keys(CommaDict, Keys). 502keys({CommaDict}, Keys) => 503 comma_dict_keys(CommaDict, Keys). 504 505comma_dict_keys((Key:_,T), Keys) => 506 Keys = [Key|KT], 507 comma_dict_keys(T, KT). 508comma_dict_keys(Key:_, Keys) => 509 Keys = [Key]. 510 511%! key(+Dict, ?Key) is nondet. 512% 513% True when Key is a key in Dict. Backtracking enumerates all known 514% keys. 515% 516% @compat PIP. Note that this predicate handle a SWI-Prolog dict, a 517% {k:v, ...} term as well as py({k:v, ...}. 518 519key(Dict, Key), is_dict(Dict) => 520 dict_pairs(Dict, _Tag, Pairs), 521 member(Key-_, Pairs). 522key(py({CommaDict}), Keys) => 523 comma_dict_key(CommaDict, Keys). 524key({CommaDict}, Keys) => 525 comma_dict_key(CommaDict, Keys). 526 527comma_dict_key((Key:_,_), Key). 528comma_dict_key((_,T), Key) :- 529 comma_dict_key(T, Key). 530 531%! items(+Dict, ?Items) is det. 532% 533% True when Items is a list of Key:Value that appear in Dict. 534% 535% @compat PIP. Note that this predicate handle a SWI-Prolog dict, a 536% {k:v, ...} term as well as py({k:v, ...}. 537 538items(Dict, Items), is_dict(Dict) => 539 dict_pairs(Dict, _, Pairs), 540 maplist(pair_item, Pairs, Items). 541items(py({CommaDict}), Keys) => 542 comma_dict_items(CommaDict, Keys). 543items({CommaDict}, Keys) => 544 comma_dict_items(CommaDict, Keys). 545 546pair_item(K-V, K:V). 547 548comma_dict_items((Key:Value,T), Keys) => 549 Keys = [Key:Value|KT], 550 comma_dict_items(T, KT). 551comma_dict_items(Key:Value, Keys) => 552 Keys = [Key:Value]. 553 554 555 /******************************* 556 * SHELL * 557 *******************************/ 558 559%! py_shell 560% 561% Start an interactive Python REPL loop using the embedded Python 562% interpreter. The interpreter first imports `janus` as below. 563% 564% from janus import * 565% 566% So, we can do 567% 568% ?- py_shell. 569% ... 570% >>> query_once("writeln(X)", {"X":"Hello world"}) 571% Hello world 572% {'truth': True} 573% 574% If possible, we enable command line editing using the GNU readline 575% library. 576% 577% When used in an environment where Prolog does not use the file 578% handles 0,1,2 for the standard streams, e.g., in `swipl-win`, 579% Python's I/O is rebound to use Prolog's I/O. This includes Prolog's 580% command line editor, resulting in a mixed history of Prolog and 581% Pythin commands. 582 583py_shell :- 584 import_janus, 585 py_call(janus_swi:interact(), _). 586 587import_janus :- 588 py_call(sys:hexversion, V), 589 V >= 0x030A0000, % >= 3.10 590 !, 591 py_run("from janus_swi import *", py{}, py{}, _, []). 592import_janus :- 593 print_message(warning, janus(py_shell(no_janus))). 594 595 596 /******************************* 597 * UTILITIES * 598 *******************************/ 599 600%! py_pp(+Term) is det. 601%! py_pp(+Term, +Options) is det. 602%! py_pp(+Stream, +Term, +Options) is det. 603% 604% Pretty prints the Prolog translation of a Python data structure in 605% Python syntax. This exploits pformat() from the Python module 606% `pprint` to do the actual formatting. Options is translated into 607% keyword arguments passed to pprint.pformat(). In addition, the 608% option nl(Bool) is processed. When `true` (default), we use 609% pprint.pp(), which makes the output followed by a newline. For 610% example: 611% 612% ``` 613% ?- py_pp(py{a:1, l:[1,2,3], size:1000000}, 614% [underscore_numbers(true)]). 615% {'a': 1, 'l': [1, 2, 3], 'size': 1_000_000} 616% ``` 617% 618% @compat PIP 619 620py_pp(Term) :- 621 py_pp(current_output, Term, []). 622 623py_pp(Term, Options) :- 624 py_pp(current_output, Term, Options). 625 626py_pp(Stream, Term, Options) :- 627 select_option(nl(NL), Options, Options1, true), 628 ( NL == true 629 -> Method = pp 630 ; Method = pformat 631 ), 632 opts_kws(Options1, Kws), 633 PFormat =.. [Method, Term|Kws], 634 py_call(pprint:PFormat, String), 635 write(Stream, String). 636 637opts_kws(Options, Kws) :- 638 dict_options(Dict, Options), 639 dict_pairs(Dict, _, Pairs), 640 maplist(pair_kws, Pairs, Kws). 641 642pair_kws(Name-Value, Name=Value). 643 644 645%! py_object_dir(+ObjRef, -List) is det. 646%! py_object_dict(+ObjRef, -Dict) is det. 647% 648% Examine attributes of an object. The predicate py_object_dir/2 649% fetches the names of all attributes, while py_object_dir/2 gets a 650% dict with all attributes and their values. 651% 652% @compat PIP 653 654py_object_dir(ObjRef, List) :- 655 py_call(ObjRef:'__dir__'(), List). 656 657py_object_dict(ObjRef, Dict) :- 658 py_call(ObjRef:'__dict__', Dict). 659 660%! py_obj_dir(+ObjRef, -List) is det. 661%! py_obj_dict(+ObjRef, -Dict) is det. 662% 663% @deprecated Use py_object_dir/2 or py_object_dict/2. 664 665py_obj_dir(ObjRef, List) :- 666 py_object_dir(ObjRef, List). 667 668py_obj_dict(ObjRef, Dict) :- 669 py_object_dict(ObjRef, Dict). 670 671 672%! py_type(+ObjRef, -Type:atom) is det. 673% 674% True when Type is the name of the type of ObjRef. This is the same 675% as ``type(ObjRef).__name__`` in Python. 676% 677% @compat PIP 678 679py_type(ObjRef, Type) :- 680 py_call(type(ObjRef):'__name__', Type). 681 682%! py_isinstance(+ObjRef, +Type) is semidet. 683% 684% True if ObjRef is an instance of Type or an instance of one of the 685% sub types of Type. This is the same as ``isinstance(ObjRef)`` in 686% Python. 687% 688% @arg Type is either a term `Module:Type` or a plain atom to refer to 689% a built-in type. 690% 691% @compat PIP 692 693py_isinstance(Obj, Module:Type) => 694 py_call(isinstance(Obj, eval(Module:Type)), @true). 695py_isinstance(Obj, Type) => 696 py_call(isinstance(Obj, eval(sys:modules:'__getitem__'(builtins):Type)), @true). 697 698%! py_module_exists(+Module) is semidet. 699% 700% True if Module is a currently loaded Python module or it can be 701% loaded. 702% 703% @compat PIP 704 705py_module_exists(Module) :- 706 must_be(atom, Module), 707 py_call(sys:modules:'__contains__'(Module), @true), 708 !. 709py_module_exists(Module) :- 710 py_call(importlib:util:find_spec(Module), R), 711 R \== @none, 712 py_free(R). 713 714%! py_hasattr(+ModuleOrObj, ?Name) is nondet. 715% 716% True when Name is an attribute of Module. The name is derived from 717% the Python built-in hasattr(). If Name is unbound, this enumerates 718% the members of py_object_dir/2. 719% 720% @arg ModuleOrObj If this is an atom it refers to a module, otherwise 721% it must be a Python object reference. 722% 723% @compat PIP 724 725py_hasattr(ModuleOrObj, Name) :- 726 var(Name), 727 !, 728 py_object_dir(ModuleOrObj, Names), 729 member(Name, Names). 730py_hasattr(ModuleOrObj, Name) :- 731 must_be(atom, Name), 732 ( atom(ModuleOrObj) 733 -> py_call(ModuleOrObj:'__name__'), % force loading 734 py_call(hasattr(eval(sys:modules:'__getitem__'(ModuleOrObj)), Name), @true) 735 ; py_call(hasattr(ModuleOrObj, Name), @true) 736 ). 737 738 739%! py_import(+Spec, +Options) is det. 740% 741% Import a Python module. Janus imports modules automatically when 742% referred in py_call/2 and related predicates. Importing a module 743% implies the module is loaded using Python's ``__import__()`` 744% built-in and added to a table that maps Prolog atoms to imported 745% modules. This predicate explicitly imports a module and allows it to 746% be associated with a different name. This is useful for loading 747% _nested modules_, i.e., a specific module from a Python package as 748% well as for avoiding conflicts. For example, with the Python 749% `selenium` package installed, we can do in Python: 750% 751% >>> from selenium import webdriver 752% >>> browser = webdriver.Chrome() 753% 754% Without this predicate, we can do 755% 756% ?- py_call('selenium.webdriver':'Chrome'(), Chrome). 757% 758% For a single call this is fine, but for making multiple calls it 759% gets cumbersome. With this predicate we can write this. 760% 761% ?- py_import('selenium.webdriver', []). 762% ?- py_call(webdriver:'Chrome'(), Chrome). 763% 764% By default, the imported module is associated to an atom created 765% from the last segment of the dotted name. Below we use an explicit 766% name. 767% 768% ?- py_import('selenium.webdriver', [as(browser)]). 769% ?- py_call(browser:'Chrome'(), Chrome). 770% 771% @error permission_error(import_as, py_module, As) if there is 772% already a module associated with As. 773 774py_import(Spec, Options) :- 775 option(as(_), Options), 776 !, 777 py_import_(Spec, Options). 778py_import(Spec, Options) :- 779 split_string(Spec, ".", "", Parts), 780 last(Parts, Last), 781 atom_string(As, Last), 782 py_import_(Spec, [as(As)|Options]). 783 784%! py_module(+Module:atom, +Source:string) is det. 785% 786% Load Source into the Python module Module. This is intended to be 787% used together with the `string` _quasi quotation_ that supports long 788% strings in SWI-Prolog. For example: 789% 790% ``` 791% :- use_module(library(strings)). 792% :- py_module(hello, 793% {|string|| 794% | def say_hello_to(s): 795% | print(f"hello {s}") 796% |}). 797% ``` 798% 799% Calling this predicate multiple times with the same Module and 800% Source is a no-op. Called with a different source creates a new 801% Python module that replaces the old in the global namespace. 802% 803% @error python_error(Type, Data) is raised if Python raises an error. 804 805:- dynamic py_dyn_module/2 as volatile. 806 807py_module(Module, Source) :- 808 variant_sha1(Source, Hash), 809 ( py_dyn_module(Module, Hash) 810 -> true 811 ; py_call(janus:import_module_from_string(Module, Source)), 812 ( retract(py_dyn_module(Module, _)) 813 -> py_update_module_cache(Module) 814 ; true 815 ), 816 asserta(py_dyn_module(Module, Hash)) 817 ). 818 819 820 /******************************* 821 * INIT * 822 *******************************/ 823 824:- dynamic py_venv/2 as volatile. 825:- dynamic py_is_initialized/0 as volatile. 826 827% py_initialize is det. 828% 829% Used as a callback from C for lazy initialization of Python. 830 831py_initialize :- 832 getenv('VIRTUAL_ENV', VEnv), 833 prolog_to_os_filename(VEnvDir, VEnv), 834 atom_concat(VEnvDir, '/pyvenv.cfg', Cfg), 835 venv_config(Cfg, Config), 836 !, 837 current_prolog_flag(executable, Program), 838 current_prolog_flag(py_argv, Argv), 839 py_initialize(Program, ['-I'|Argv], []), 840 py_setattr(sys, prefix, VEnv), 841 venv_update_path(VEnvDir, Config). 842py_initialize :- 843 current_prolog_flag(executable, Program), 844 current_prolog_flag(py_argv, Argv), 845 py_initialize(Program, Argv, []). 846 847venv_config(File, Config) :- 848 access_file(File, read), 849 read_file_to_string(File, String, []), 850 split_string(String, "\n", "\n\r", Lines), 851 convlist(venv_config_line, Lines, Config). 852 853venv_config_line(Line, Config) :- 854 sub_string(Line, B, _, A, "="), 855 !, 856 sub_string(Line, 0, B, _, NameS), 857 split_string(NameS, "", "\t\s", [NameS2]), 858 atom_string(Name, NameS2), 859 sub_string(Line, _, A, 0, ValueS), 860 split_string(ValueS, "", "\t\s", [ValueS2]), 861 ( number_string(Value, ValueS2) 862 -> true 863 ; atom_string(Value, ValueS2) 864 ), 865 Config =.. [Name,Value]. 866 867venv_update_path(VEnvDir, Options) :- 868 py_call(sys:version_info, Info), % Tuple 869 Info =.. [_,Major,Minor|_], 870 format(string(EnvSiteDir), 871 '~w/lib/python~w.~w/site-packages', 872 [VEnvDir, Major, Minor]), 873 prolog_to_os_filename(EnvSiteDir, PyEnvSiteDir), 874 ( exists_directory(EnvSiteDir) 875 -> true 876 ; print_message(warning, 877 janus(venv(no_site_package_dir(VEnvDir, EnvSiteDir)))) 878 ), 879 py_call(sys:path, Path0), 880 ( option('include-system-site-packages'(true), Options) 881 -> partition(is_site_dir, Path0, PkgPath, SysPath), 882 append([SysPath,[PyEnvSiteDir], PkgPath], Path) 883 ; exclude(is_site_dir, Path0, Path1), 884 append(Path1, [PyEnvSiteDir], Path) 885 ), 886 py_setattr(sys, path, Path), 887 print_message(silent, janus(venv(VEnvDir, EnvSiteDir))), 888 asserta(py_venv(VEnvDir, EnvSiteDir)). 889 890is_site_dir(OsDir) :- 891 prolog_to_os_filename(PlDir, OsDir), 892 file_base_name(PlDir, Dir0), 893 downcase_atom(Dir0, Dir), 894 no_env_dir(Dir). 895 896no_env_dir('site-packages'). 897no_env_dir('dist-packages'). 898 899%! py_initialize(+Program, +Argv, +Options) is det. 900% 901% Initialize and configure the embedded Python system. If this 902% predicate is not called before any other call to Python such as 903% py_call/2, it is called _lazily_, passing the Prolog executable as 904% Program, passing Argv from the Prolog flag `py_argv` and an empty 905% Options list. 906% 907% Calling this predicate while the Python is already initialized is 908% a no-op. This predicate is thread-safe, where the first call 909% initializes Python. 910% 911% In addition to initializing the Python system, it 912% 913% - Adds the directory holding `janus.py` to the Python module 914% search path. 915% - If Prolog I/O is not connected to the file handles 0,1,2, 916% it rebinds Python I/O to use the Prolog I/O. 917% 918% @arg Options is currently ignored. It will be used to provide 919% additional configuration options. 920 921py_initialize(Program, Argv, Options) :- 922 ( py_initialize_(Program, Argv, Options) 923 -> absolute_file_name(library('python/janus.py'), Janus, 924 [ access(read) ]), 925 file_directory_name(Janus, PythonDir), 926 py_add_lib_dir(PythonDir, first), 927 py_connect_io, 928 repl_add_cwd, 929 asserta(py_is_initialized) 930 ; true 931 ). 932 933%! py_connect_io is det. 934% 935% If SWI-Prolog console streams are bound to something non-standard, 936% bind the Python console I/O to our streans. 937 938py_connect_io :- 939 maplist(non_file_stream, 940 [0-user_input, 1-user_output, 2-user_error], 941 NonFiles), 942 Call =.. [connect_io|NonFiles], 943 py_call(janus_swi:Call). 944 945non_file_stream(Expect-Stream, Bool) :- 946 ( stream_property(Stream, file_no(Expect)) 947 -> Bool = @false 948 ; Bool = @true 949 ). 950 951 /******************************* 952 * PATHS * 953 *******************************/ 954 955%! py_lib_dirs(-Dirs) is det. 956% 957% True when Dirs is a list of directories searched for Python modules. 958% The elements of Dirs are in Prolog canonical notation. 959% 960% @compat PIP 961 962py_lib_dirs(Dirs) :- 963 py_call(sys:path, Dirs0), 964 maplist(prolog_to_os_filename, Dirs, Dirs0). 965 966%! py_add_lib_dir(+Dir) is det. 967%! py_add_lib_dir(+Dir, +Where) is det. 968% 969% Add a directory to the Python module search path. In the second 970% form, Where is one of `first` or `last`. py_add_lib_dir/1 adds the 971% directory as `last`. The property `sys:path` is not modified if it 972% already contains Dir. 973% 974% Dir is in Prolog notation. The added directory is converted to an 975% absolute path using the OS notation using prolog_to_os_filename/2. 976% 977% If Dir is a _relative_ path, it is taken relative to Prolog source 978% file when used as a _directive_ and relative to the process working 979% directory when called as a predicate. 980% 981% @compat PIP. Note that SWI-Prolog uses POSIX file conventions 982% internally, mapping to OS conventions inside the predicates that 983% deal with files or explicitly using prolog_to_os_filename/2. Other 984% systems may use the native file conventions in Prolog. 985 986:- multifile system:term_expansion/2. 987 988systemterm_expansion((:- py_add_lib_dir(Dir0)), Directive) :- 989 system:term_expansion((:- py_add_lib_dir(Dir0, last)), Directive). 990systemterm_expansion((:- py_add_lib_dir(Dir0, Where)), 991 (:- initialization(py_add_lib_dir(Dir, Where), now))) :- 992 \+ (atomic(Dir0), is_absolute_file_name(Dir0)), 993 prolog_load_context(directory, CWD), 994 absolute_file_name(Dir0, Dir, 995 [ relative_to(CWD), 996 file_type(directory), 997 access(read) 998 ]). 999 1000py_add_lib_dir(Dir) :- 1001 py_add_lib_dir(Dir, last). 1002 1003py_add_lib_dir(Dir, Where) :- 1004 atomic(Dir), 1005 !, 1006 absolute_file_name(Dir, AbsDir), 1007 prolog_to_os_filename(AbsDir, OSDir), 1008 py_add_lib_dir_(OSDir, Where). 1009py_add_lib_dir(Alias, Where) :- 1010 absolute_file_name(Alias, AbsDir, 1011 [ file_type(directory), 1012 access(read) 1013 ]), 1014 prolog_to_os_filename(AbsDir, OSDir), 1015 py_add_lib_dir_(OSDir, Where). 1016 1017py_add_lib_dir_(OSDir, Where) :- 1018 ( py_call(sys:path, Dirs0), 1019 memberchk(OSDir, Dirs0) 1020 -> true 1021 ; Where == last 1022 -> py_call(sys:path:append(OSDir), _) 1023 ; Where == first 1024 -> py_call(sys:path:insert(0, OSDir), _) 1025 ; must_be(oneof([first,last]), Where) 1026 ). 1027 1028:- det(repl_add_cwd/0). 1029repl_add_cwd :- 1030 current_prolog_flag(break_level, Level), 1031 Level >= 0, 1032 !, 1033 ( py_call(sys:path:count(''), N), 1034 N > 0 1035 -> true 1036 ; print_message(informational, janus(add_cwd)), 1037 py_add_lib_dir_('', first) 1038 ). 1039repl_add_cwd. 1040 1041:- multifile 1042 prolog:repl_loop_hook/2. 1043 1044prologrepl_loop_hook(begin, Level) :- 1045 Level >= 0, 1046 py_is_initialized, 1047 repl_add_cwd. 1048 1049 1050 /******************************* 1051 * CALLBACK * 1052 *******************************/ 1053 1054:- dynamic py_call_cache/8 as volatile. 1055 1056:- meta_predicate py_call_string(, , ). 1057 1058% py_call_string(:String, +DictIn, -Dict) is nondet. 1059% 1060% Support janus.query_once() and janus.query(). Parses String into a goal 1061% term. Next, all variables from the goal term that appear in DictIn 1062% are bound to the value from this dict. Dict is created from the 1063% remaining variables, unless they start with an underscore (e.g., 1064% `_Time`) and the key `truth. On success, the Dict values contain 1065% the bindings from the answer and `truth` is either `true` or 1066% `Undefined`. On failure, the Dict values are bound to `None` and the 1067% `truth` is `false`. 1068% 1069% Parsing and distributing the variables over the two dicts is cached. 1070 1071py_call_string(M:String, Input, Dict) :- 1072 py_call_cache(String, Input, TV, M, Goal, Dict, Truth, OutVars), 1073 !, 1074 py_call(TV, M:Goal, Truth, OutVars). 1075py_call_string(M:String, Input, Dict) :- 1076 term_string(Goal, String, [variable_names(Map)]), 1077 unbind_dict(Input, VInput), 1078 exclude(not_in_projection(VInput), Map, OutBindings), 1079 dict_create(Dict, bindings, [truth=Truth|OutBindings]), 1080 maplist(arg(2), OutBindings, OutVars), 1081 TV = Input.get(truth, 'PLAIN_TRUTHVALS'), 1082 asserta(py_call_cache(String, VInput, TV, M, Goal, Dict, Truth, OutVars)), 1083 VInput = Input, 1084 py_call(TV, M:Goal, Truth, OutVars). 1085 1086py_call('NO_TRUTHVALS', M:Goal, Truth, OutVars) => 1087 ( call(M:Goal) 1088 *-> bind_status_no_no_truthvals(Truth) 1089 ; Truth = @false, 1090 maplist(bind_none, OutVars) 1091 ). 1092py_call('PLAIN_TRUTHVALS', M:Goal, Truth, OutVars) => 1093 ( call(M:Goal) 1094 *-> bind_status_plain_truthvals(Truth) 1095 ; Truth = @false, 1096 maplist(bind_none, OutVars) 1097 ). 1098py_call('DELAY_LISTS', M:Goal, Truth, OutVars) => 1099 ( call_delays(M:Goal, Delays) 1100 *-> bind_status_delay_lists(Delays, Truth) 1101 ; Truth = @false, 1102 maplist(bind_none, OutVars) 1103 ). 1104py_call('RESIDUAL_PROGRAM', M:Goal, Truth, OutVars) => 1105 ( call_delays(M:Goal, Delays) 1106 *-> bind_status_residual_program(Delays, Truth) 1107 ; Truth = @false, 1108 maplist(bind_none, OutVars) 1109 ). 1110 1111not_in_projection(Input, Name=Value) :- 1112 ( get_dict(Name, Input, Value) 1113 -> true 1114 ; sub_atom(Name, 0, _, _, '_') 1115 ). 1116 1117bind_none(@none). 1118 1119bind_status_no_no_truthvals(@true). 1120 1121bind_status_plain_truthvals(Truth) => 1122 ( '$tbl_delay_list'([]) 1123 -> Truth = @true 1124 ; py_undefined(Truth) 1125 ). 1126 1127bind_status_delay_lists(true, Truth) => 1128 Truth = @true. 1129bind_status_delay_lists(Delays, Truth) => 1130 py_call(janus:'Undefined'(prolog(Delays)), Truth). 1131 1132bind_status_residual_program(true, Truth) => 1133 Truth = @true. 1134bind_status_residual_program(Delays, Truth) => 1135 delays_residual_program(Delays, Program), 1136 py_call(janus:'Undefined'(prolog(Program)), Truth). 1137 1138py_undefined(X) :- 1139 py_call(janus:undefined, X). 1140 1141unbind_dict(Dict0, Dict) :- 1142 dict_pairs(Dict0, Tag, Pairs0), 1143 maplist(unbind, Pairs0, Pairs), 1144 dict_pairs(Dict, Tag, Pairs). 1145 1146unbind(Name-_, Name-_) :- 1147 sub_atom(Name, 0, 1, _, Char1), 1148 char_type(Char1, prolog_var_start), 1149 !. 1150unbind(NonVar, NonVar). 1151 1152 1153 /******************************* 1154 * SUPPORT PYTHON CALLS * 1155 *******************************/ 1156 1157:- public 1158 px_cmd/3, 1159 px_call/4, 1160 px_comp/7. 1161 1162% These predicates are helpers for the corresponding Python functions 1163% in janus.py. 1164 1165 1166% px_call(+Input:tuple, +Module, -Pred, -Ret) 1167% 1168% Supports px_qdet() and apply(). Note that these predicates 1169% explicitly address predicates in a particular module. For meta 1170% predicates, this implies they also control the context module. This 1171% leads to ``janus.cmd("consult", "consult", file)`` to consult _file_ 1172% into the module `consult`, which is not what we want. Therefore we 1173% set the context module to `user`, which is better, but probably also 1174% not what we want. 1175 1176px_call(-(), Module, Pred, Ret) => 1177 @(call(Module:Pred, Ret), user). 1178px_call(-(A1), Module, Pred, Ret) => 1179 @(call(Module:Pred, A1, Ret), user). 1180px_call(-(A1,A2), Module, Pred, Ret) => 1181 @(call(Module:Pred, A1, A2, Ret), user). 1182px_call(-(A1,A2,A3), Module, Pred, Ret) => 1183 @(call(Module:Pred, A1, A2, A3, Ret), user). 1184px_call(-(A1,A2,A3,A4), Module, Pred, Ret) => 1185 @(call(Module:Pred, A1, A2, A3, A4, Ret), user). 1186px_call(Tuple, Module, Pred, Ret) => 1187 compound_name_arguments(Tuple, _, Args), 1188 append(Args, [Ret], GArgs), 1189 Goal =.. [Pred|GArgs], 1190 @(Module:Goal, user). 1191 1192px_cmd(Module, Pred, Tuple) :- 1193 ( compound(Tuple) 1194 -> compound_name_arguments(Tuple, _, Args), 1195 Goal =.. [Pred|Args] 1196 ; Goal = Pred 1197 ), 1198 @(Module:Goal, user). 1199 1200px_comp(Module, Pred, Tuple, Vars, Set, TV, Ret) :- 1201 length(Out, Vars), 1202 ( compound(Tuple) 1203 -> compound_name_arguments(Tuple, _, Args), 1204 append(Args, Out, GArgs), 1205 Goal =.. [Pred|GArgs] 1206 ; Goal =.. [Pred|Out] 1207 ), 1208 compound_name_arguments(OTempl0, -, Out), 1209 tv_goal_and_template(TV, @(Module:Goal, user), FGoal, OTempl0, OTempl), 1210 findall(OTempl, FGoal, Ret0), 1211 ( Set == @true 1212 -> sort(Ret0, Ret) 1213 ; Ret = Ret0 1214 ). 1215 1216:- meta_predicate 1217 call_delays_py(, ). 1218 1219% 0,1,2: TruthVal(Enum) from janus.py 1220tv_goal_and_template('NO_TRUTHVALS', 1221 Goal, Goal, Templ, Templ) :- !. 1222tv_goal_and_template('PLAIN_TRUTHVALS', 1223 Goal, ucall(Goal, TV), Templ, -(Templ,TV)) :- !. 1224tv_goal_and_template('DELAY_LISTS', 1225 Goal, call_delays_py(Goal, TV), Templ, -(Templ,TV)) :- !. 1226tv_goal_and_template(Mode, _, _, _, _) :- 1227 domain_error("px_comp() truth", Mode). 1228 1229:- public 1230 ucall/2, 1231 call_delays_py/2. 1232 1233ucall(Goal, TV) :- 1234 call(Goal), 1235 ( '$tbl_delay_list'([]) 1236 -> TV = 1 1237 ; TV = 2 1238 ). 1239 1240call_delays_py(Goal, PyDelays) :- 1241 call_delays(Goal, Delays), 1242 ( Delays == true 1243 -> PyDelays = [] 1244 ; comma_list(Delays, Array), 1245 maplist(term_string, Array, PyDelays) 1246 ). 1247 1248 1249 /******************************* 1250 * PYTHON I/O * 1251 *******************************/ 1252 1253% py_write(+Stream, -String) is det. 1254% py_readline(+Stream, +Size, +Prompt, +Line) is det. 1255% 1256% Called from redefined Python console I/O to write/read using the 1257% Prolog streams. 1258 1259:- '$hide'((py_write/1, 1260 py_readline/4)). 1261 1262py_write(Stream, String) :- 1263 notrace(format(Stream, '~s', [String])). 1264 1265py_readline(Stream, Size, Prompt, Line) :- 1266 notrace(py_readline_(Stream, Size, Prompt, Line)). 1267 1268py_readline_(Stream, _Size, Prompt, Line) :- 1269 prompt1(Prompt), 1270 read_line_to_string(Stream, Read), 1271 ( Read == end_of_file 1272 -> Line = "" 1273 ; string_concat(Read, "\n", Line), 1274 py_add_history(Read) 1275 ). 1276 1277py_add_history(Line) :- 1278 ignore(catch(prolog:history(user_input, add(Line)), _, true)). 1279 1280 1281 /******************************* 1282 * COMPILING * 1283 *******************************/ 1284 1285% py_consult(+File, +Data, +Module) is det. 1286% 1287% Support janus.consult(file, data=None, module='user'). 1288 1289:- public py_consult/3. 1290py_consult(File, @none, Module) => 1291 consult(Module:File). 1292py_consult(File, Data, Module) => 1293 setup_call_cleanup( 1294 open_string(Data, In), 1295 load_files(Module:File, [stream(In)]), 1296 close(In)). 1297 1298 1299 /******************************* 1300 * MESSAGES * 1301 *******************************/ 1302 1303:- multifile 1304 prolog:error_message//1, 1305 prolog:message_context//1, 1306 prolog:message//1. 1307 1308prologerror_message(python_error(Class, Value)) --> 1309 { py_str(Value, Message) 1310 }, 1311 [ 'Python ', ansi(code, "'~w'", [Class]), ':', nl, 1312 ' ~w'-[Message] 1313 ]. 1314prologerror_message(permission_error(import_as, py_module, As)) --> 1315 [ 'Janus: No permission to import a module as ', ansi(code, '~q', As), 1316 ': module exists.' 1317 ]. 1318 1319prologmessage_context(context(_, PythonCtx)) --> 1320 { nonvar(PythonCtx), 1321 PythonCtx = python_stack(Stack), 1322 current_prolog_flag(py_backtrace, true), 1323 py_is_object(Stack), 1324 !, 1325 current_prolog_flag(py_backtrace_depth, Depth), 1326 py_call(traceback:format_tb(Stack, Depth), Frames) 1327 }, 1328 [ nl, 'Python stack:', nl ], 1329 sequence(py_stack_frame, Frames). 1330 1331py_stack_frame(String) --> 1332 { split_string(String, "\n", "", Lines) 1333 }, 1334 sequence(msg_line, [nl], Lines). 1335 1336msg_line(Line) --> 1337 [ '~s'-[Line] ]. 1338 1339prologmessage(janus(Msg)) --> 1340 message(Msg). 1341 1342message(version(Janus, Python)) --> 1343 [ 'Janus ~w embeds Python ~w'-[Janus, Python] ]. 1344message(venv(Dir, _EnvSiteDir)) --> 1345 [ 'Janus: using venv from ~p'-[Dir] ]. 1346message(venv(no_site_package_dir(VEnvDir, Dir))) --> 1347 [ 'Janus: venv dirrectory ~p does not contain ~p'-[VEnvDir, Dir] ]. 1348message(py_shell(no_janus)) --> 1349 [ 'Janus: py_shell/0: Importing janus into the Python shell requires Python 3.10 or later.', nl, 1350 'Run "', ansi(code, 'from janus import *', []), '" in the Python shell to import janus.' 1351 ]. 1352message(add_cwd) --> 1353 [ 'Interactive session; added `.` to Python `sys.path`'-[] ]