Python Type Checker Kuenzanisa: Empty Container Inference

Nei Mumidziyo Musina Kupwanya Python Type Checkers - Uye Zvamungaite Nezvazvo

Sitimu yekutaipa zvishoma nezvishoma yePython yakura zvakanyanya kubvira PEP 484 yakaunza mazano emhando muna 2015. Nhasi, mamiriyoni evagadziri vanovimba nema static type checkers kubata tsikidzi vasati vatanga kugadzira. Asi pane yakavanzika, inoshungurudza kona yemhando system ichiri kukwira kunyange mainjiniya ane ruzivo: imhando ipi ine mudziyo usina chinhu? Paunonyora x = [] pasina chirevo, cheki yako yemhando inofanirwa kufungidzira - uye macheki akasiyana anofungidzira zvakasiyana. Kusiyana uku kunogadzira matambudziko chaiwo kuzvikwata zvinochengeta macodebase makuru, uko kuchinja kana kubatanidza macheki emhando kunogona kuburitsa mazana ezvikanganiso zvisingatarisirwi nehusiku humwe.

Chinyorwa ichi chinoparura maitirwo mana makuru emhando yePython - mypy, pyright, pytype, uye pyre - anobata seisina chinhu mugaba, nei vasingabvumirani, uye ndeapi mazano anoshanda aungatora kunyora-yakachengeteka Python zvisinei nesarudzo yako yekushandisa.

Dambudziko Rakakura: Zvigubhu Zvisina Zvisina Kujeka Zvinogara Zvakajeka

Funga nezvemutsara uyu usina mhosva wePython: zvawanikwa = []. zvabuda ilist[int]? Alist[str]? Alist[dict[str, Any]]? Pasina mamwe mamiriro, hapana nzira yekuziva. Iyo Python yekumhanyisa nguva haina basa - zvinyorwa zvine heterogeneous nemasikirwo - asi static mhando yekutarisa inofanirwa kugovera rudzi rwekongiri kune yega yega yega kuti vaite basa ravo. Izvi zvinogadzira kusawirirana kwakakosha pakati pePython's dynamic flexibility uye vimbiso dzinoedza kupa.

Dambudziko rinosangana nemaduramazwi nemaseti. Chisina chinhu {} chinopatsanurwa sedict, kwete seti, iyo inowedzera kusajeka kwechigadzirwa pamusoro pemhando-yemhando yekusajeka. Uye midziyo inested — funga defaultdict(list) or results = {k: [] for k in keys} — push inference engines to their limits. Imwe neimwe yemhando yekuongorora yakagadzira yayo yega heuristics, uye misiyano yakakosha kupfuura zvinozivikanwa nevazhinji vanogadzira.

Mumasisitimu ekugadzira anogadzirisa mabasa chaiwo - ingave iri CRM inobata marekodhi evatengi, moduru yeinvoyisi inogadzira zvinhu zvemutsara, kana pombi yekuongorora inounganidza metrics - midziyo isina chinhu inogara ichionekwa sematangisa maitiro. Kukanganisa mhando dzavo hakungobudisi yambiro; inogona kuvhara tsikidzi chaidzo dzinotsvedza kusvika panguva yekumhanya.

Mypy: Deferred Inference NeIplicit Any

Mypy, yekare uye yakanyanya kutorwa Python mhando yekutarisa, inotora nzira yakapfava kumidziyo isina chinhu. Kana yasangana nex = [] pachiyero chekushanda, inoedza kudefer the type decision uye infer the element type kubva mukushandiswa kunotevera. Kana ukanyora x = [] ichiteverwa nex.append(42), mypy ichaita list[int]. Iyi "join" zano rinoshanda zvinoshamisa kune zviitiko zviri nyore apo mudziyo uzere mukati mechikamu chimwe chete.

Zvisinei, maitiro emypy anochinja zvakanyanya zvichienderana nemamiriro uye kusimba kwezvirongwa. Pamodule scope (yepamusoro-level code), kana mudziyo uchipfuudzwa kune rimwe basa risati ragarwa, mypy inowanzo dzokera kulist[Chero]. Pasi pe--strict mureza, izvi zvinokonzeresa kukanganisa, asi muodhidhiyo inodarika chinyararire. Izvi zvinoreva kuti zvikwata zvinomhanya zvisingaite zvisina kuomesesa zvinogona kuunganidza akawanda emidziyo yakanyatsotaipa iyo inoita semapuku ekupunyuka kubva mumhando system, ichikunda chinangwa chayo.

Umwe hunhu husina kunyatsojeka: mypy versions isati yasvika 0.990 dzimwe nguva yaizoti list[Hazvizivikanwi] mukati zvobva zvawedzera kuzita[Chero] pane basa. Mushure me-0.990, iyo fungidziro yakasimbiswa, asi shanduko yakaputsa nhamba inokatyamadza yemakodhi epasirese epasirese anga achitsamira pamaitiro ekuregedzera asingazvizive. Iri ndiro dingindira rinodzokororwa — shanduko kuisina chinhu inference ndezvimwe zvinokanganisa mhando yekutarisa zvigadziriso nekuti mapatani anowanikwa kwese.

Pyright: Yakasimba Inference uye iyo "Isingazivikanwe" Type

Pyright, yakagadziridzwa neMicrosoft uye inopa simba Pylance muVS Code, inotora huzivi hwakasiyana. Pane kuti udzokere chinyararire kuChero, pyright inosiyanisa pakati peUnknown (rudzi rwusati rwazivikanwa) neChero (kubuda pachena kwekutarisa mhando). Paunonyora x = [] mune pyright's strict mode, zvinotora list[Hazvizivikanwe] uye inoshuma kuongororwa, zvichikumanikidza kuti upe chirevo.

Pyright ine hukasha zvakare pamusoro pekutetepa mukati mechikamu. Kana ukanyora:

• x = [] inoteverwa nex.append("hello") — pyright infers list[str]
• x = [] ichiteverwa nex.append(1) ipapo x.append("hello") — pyright infers list[int | str]
• x = [] yakapfuura yakananga kune basa rinotarisira list[int] — pyright infers list[int] kubva ku call-site context
• x = [] akadzoka kubva kubasa risina rondedzero yemhando yekudzoka — pyright inoshuma kukanganisa pane kufungidzira

Iyi bidirectional inference (uchishandisa ese anotevera mashandisiro nemhando dzinotarisirwa kubva kunzvimbo dzekufona) inoita kuti pyright inyatsojeka kupfuura mypy yemidziyo isina chinhu. The tradeoff is verbosity: pyright's yakasimba modhi mireza ingangoita 30-40% zvimwe nyaya pane yakajairwa isina kunyorwa codebase kana ichienzaniswa neiyo mypy's yakasimba modhi, maererano nekuongorora kubva kune akati wandei akavhurika-sosi migration mishumo. Kuzvikwata zvinovaka masisitimu akaomesesa ekudzokera shure - toti, chikuva chinobata 207 akabatana mamodules anotora CRM, payroll, uye analytics - kuomarara kwepyright kunobata zvisizvo zvisizvo izvo zvingangopotsa.

Pytype uye Pyre: Iyo Ishoma Inofamba Migwagwa

Google's pytype inotora pamwe nzira ine pragmatic. Panzvimbo pekuda zvirevo kana kudzokera kuChero, pytype inoshandisawongororo yepurogiramu yose kutarisa kuti mudziyo unoshandiswa sei pamiganhu yekushanda. Kana iwe ukagadzira runyoro rusina chinhu mune rimwe basa uye uchipfuudza kune rimwe rinowedzera nhamba, pytype inogona kazhinji infer list[int] pasina chero zvirevo zvachose. Iyi fungidziro yemuchinjiko inodhura zvakanyanya — pytype inononoka kupfuura mypy kana pyright pamakodhi mahombe - asi inoburitsa mashoma emanyepo pakodhi isina kunyorwa.

Pytype inosumawo pfungwa ye"partial types" yemidziyo isina chinhu. Ichangobva kugadzirwa [] inowana imwe mhando inokwenenzverwa zvishoma nezvishoma sezvo cheki ichisangana nekushandiswa kwakawanda. Izvi zvinoyevedza asi zvinogona kuburitsa mameseji ezvikanganiso zvinovhiringa kana rudzi rwacho rusingakwanise kunyatsogadziriswa, sekuti kana chigaba chisina chinhu chinoyerera nemumabasa akati wandei pasina kumbogarwa.

Meta's pyre, panguva iyi, inoswedera pedyo nemaitiro emypy asi nekusimba kwakasimba. Pyre anobata x = [] serondedzero[isingazivikanwe] uye inoda chirevo mumamiriro mazhinji. Apo pyre inozvisiyanisa iri mukubata kwayo empty dictionary literals used as kwargs — maitiro akajairika muwebhu framework. Pyre ine yakakosha-kesi logic yekugonesa marudzi eduramazwi kubva kune keyword nharo mamiriro, kuderedza anonotation mutoro muchimiro-inorema codebases. Tichifunga kuti maapplication echizvino-zvino padandemutande anosanganisira kushandiswa zvakanyanya kwekuvhura duramanzwi pakugadzirisa uye kubata chikumbiro, pragmatism iyi inopa mibairo.

Chaiyo-Nyika Impact: Kana Inference Divergence Inoruma

Misiyano pakati pemacheki emhando inogona kuita seyedzidzo kudzamara wasangana nayo mukodhi yekugadzira. Funga nezvemaitiro akajairwa mumashandisirwo ebhizinesi: kutanga dhata data inogarwa nemamiriro ezvinhu.

Magaba ane ngozi zvikuru asina chinhu haasi iwo echicheki mureza — ndiwo anodarika chinyararire nemhando yechero ipi, zvichiita kuti data risingawirirane riunganidzwe pasina yambiro kudzamara basa rezasi rabondera panguva yekumhanya neTypeError zvekuti hatikwanise kuronda kwarakabva.

Muenzaniso wakasimba: chikwata chekutanga fintech chakashuma kushandisa mazuva matatu kugadzirisa nyaya yekugadzira apo chinyorwa chisina chinhu, chakatangwa mubasa rekugadzirisa mubhadharo, chakanzi list[Chero] ne mypy. Rondedzero iyi yaifanirwa kunge iine Decimal zvinhu zvemari, asi nzira yekodhi yaiisa float kukosha panzvimbo. Mypy's renient inference aibvumira chinyararire. Iyo bug yakangoitika apo kukanganisa kutenderedza mu float arithmetic kwakakonzera mutsauko we$0.01 pabhechi remainvoice gumi nemaviri. Kudai vakashandisa pyright nenzira yakasimba, kana kungodonhedza rondedzero isina chinhu selist[Decimal], bug ingadai yakabatwa panguva yebudiriro.

KuMewayz, uko puratifomu inogadzira mainvoice, kuverenga kwemubhadharo, uye ongororo yemari mumaakaundi evashandisi zviuru zana nemakumi matatu nesere, rudzi urwu rwemhando yechengetedzo gap harisi dzidziso - ndiwo mutsauko uripo pakati pekubhadhara kwakaringana uye kuverengera kunodhura. Chirango chakasimba chekutaipa chakatarisana nekutanga kwegaba ndeimwe yeaya "anofinha" einjiniya maitiro anodzivirira zviitiko zvinonakidza zvekugadzira.

Dzidziso Dzakanakisisa dzeDziviriro Yemudziyo Kutanga

Zvisinei kuti ndechipi cheki cheki chinoshandiswa nechikwata chako, pane nzira dzakasimba dzekubvisa kusanzwisisika kwemudziyo usina chinhu zvachose. Chinangwa ndechekusambovimba nefungidziro yemidziyo isina chinhu - ita kuti mhando yacho ibude pachena kuitira kuti kodhi yako ibatike kune ese macheki uye kudzivirira kushanduka kwemaitiro pakati peshanduro.

1. Gara uchitsanangura zvakasiyana-siyana zvemudziyo usina chinhu. Nyora zvawanikwa: list[int] = [] pane zvawanikwa = []. Mutengo diki weverbosity hauna basa kana uchienzaniswa nenguva yekugadzirisa yakachengetwa. Iyi tsika imwe chete inobvisa zvingangoita makumi masere kubva muzana zvezvinhu zvisina chinhu zvemugaba.
2. Shandisa zviitwa zvemufekitari pamidziyo yakaoma kunzwisisa. Panzvimbo pecache = {}, nyora basa rakaita sedef make_cache() -> dict[str, list[UserRecord]]: return {}. Chirevo cherudzi rwekudzoserwa chinoita kuti mhando yavakada ive isina kujeka uye inyore yega.
3. Sarudza vagadziri vakataipa pane zvinyorwa zvemhando dzisiri diki. Nyora zvinhu: set[int] = set() pane kuvimba nenzwisiso yakatarwa. Nezvedefaultdict neCounter, garai muchipa mhando parameter: zviverengero: Counter[str] = Counter().
4. Gadzirisa maitiro ekuongorora yako yemhando yekodhi nyowani. Zvese mypy uye pyright zvinotsigira pa-faira kana pa-dhairekitori zvigadziriso. Gonesa kutarisa kwakasimba pamamodule matsva uchifambisa zvishoma nezvishoma legacy code. Izvi zvinodzivirira kuunganidzwa kwemidziyo mitsva yakanyorwa zvisina kujeka.
5. Wedzera cheki cheki chekuenzanisa kune pombi yako yeCI. Kumhanya zvese mypy ne pyright pacodebase yako kunobata mutsauko nekukasika. Kana pateni ikapfuura imwe cheki asi ikatadza imwe, chiratidzo chekuti mhando yacho haina kunyatsojeka.

Mufananidzo Muhombe: Nyora Kutarisa seChikwata Chekudzidzira

Empty container inference inopedzisira yave microcosm yedambudziko rakakura muPython's type system: kunetsana kuri pakati pekureruka nekuchengetedza. Huzivi hwePython hwekuti "tese tiri vakuru vanobvuma" hunoshanda zvakanaka kune prototyping uye zvinyorwa, asi masisitimu ekugadzira anoshandira zviuru zvevashandisi anoda vimbiso yakasimba. Nyaya yekuti macheki makuru mana asingabvumirani pachinhu chakakosha semhando ye[] inosimbisa kuti Python kutaipa ecosystem ichiri kukura.

Kuzvikwata zveinjiniya zvinovaka mapuratifomu akaomarara - ungave uri kutonga mashoma emicroservices kana system yakabatanidzwa ine mazana emamodule akabatana senge Mewayz's bhizinesi OS - zano rinoshanda rakananga: usavimbe nekufungidzira kune midziyo isina chinhu, tora cheki chemhando uye gadzirisa zvakasimba, uye bata zvinyorwa zvemhando sezvinyorwa zvinogoneka muchina. Maminetsi mashanu ashandiswa kunyora list[Invoice] pachinzvimbo che[] achakuchengetera maawa ekugadzirisa kana codebase yako ikayera.

SePEP 696 (default type parameters) nePEP 695 (type parameter syntax) zvichiramba zvichidzika mushanduro itsva dzePython, ergonomics yekutaipa pachena icharamba ichivandudzika. Mukaha uripo pakati pe "annotated" uye "unannotated" Python ichapfupika. Asi kusvika zuva iroro, mhando dzemidziyo dzakajeka dzinoramba dziri imwe yemaitiro epamusoro-ROI muPython developer's toolkit - diki diki rinobhadhara mubereko wekomboni pamamodule ese, kumhanya kwese, uye kwese kutumirwa kwekugadzira.