科學(xué)計(jì)算科研數(shù)據(jù)分析【免費(fèi)下載鏈接】astropyAstronomy and astrophysics core library項(xiàng)目地址https://gitcode.com/gh_mirrors/as/astropy點(diǎn)擊查看免費(fèi)下載本文基于 astropy 官方文檔 Custom Cosmology I/O formats 展開講解如何向 astropy Cosmology 的統(tǒng)一 I/O 框架注冊(cè)自定義格式一是面向內(nèi)存對(duì)象轉(zhuǎn)換的to_format/from_formatconvert_registry二是面向文件讀寫的read/writereadwrite_registry。讀完后你可以照著文中完整示例為任意數(shù)據(jù)形態(tài)Row、JSON 等實(shí)現(xiàn)可復(fù)用的 Cosmology 序列化/反序列化并理解其底層注冊(cè)、識(shí)別與回環(huán)驗(yàn)證機(jī)制?？蚣芨庞[兩套獨(dú)立的注冊(cè)表astropy.cosmology.io包提供了統(tǒng)一接口來讀取、寫出和轉(zhuǎn)換Cosmology對(duì)象。用戶入口是Cosmology類上的四個(gè)方法見 astropy/cosmology/io.py 的模塊說明Cosmology.read/Cosmology.write從文件讀入 / 寫出文件Cosmology.from_format/Cosmology.to_format在 Python 對(duì)象如 dict、Table與Cosmology之間轉(zhuǎn)換。這四個(gè)方法背后各掛著一套自定義注冊(cè)表而不是Table等使用的全局注冊(cè)表# astropy/cosmology/_src/io/connect.py readwrite_registry io_registry.UnifiedIORegistry() # L36read/write 用 convert_registry io_registry.UnifiedIORegistry() # L156from/to_format 用在 astropy/cosmology/_src/core.py 中它們以類變量形式綁定到Cosmologyfrom_format: ClassVar UnifiedReadWriteMethod(CosmologyFromFormat) to_format: ClassVar UnifiedReadWriteMethod(CosmologyToFormat) read: ClassVar UnifiedReadWriteMethod(CosmologyRead) write: ClassVar UnifiedReadWriteMethod(CosmologyWrite)因此為某個(gè)格式注冊(cè)自定義解析器時(shí)需要拿到對(duì)應(yīng)的注冊(cè)表Cosmology.from_format.registry即convert_registry——用于to/from_formatCosmology.read.registry即readwrite_registry——用于read/write。每注冊(cè)一個(gè)格式通常要提供三個(gè)函數(shù)reader解析為Cosmology、writer從Cosmology輸出、identifier自動(dòng)識(shí)別格式。注冊(cè)表本身的 API 位于 astropy/io/registry通用框架說明見 docs/io/registry.rst。一個(gè)值得注意的機(jī)制是CosmologyRead/CosmologyFromFormat在被子類調(diào)用時(shí)例如FlatLambdaCDM.read(...)會(huì)自動(dòng)注入關(guān)鍵字參數(shù)cosmology該子類并校驗(yàn)用戶顯式傳入的cosmology參數(shù)必須與該類或其__qualname__一致否則拋出ValueError見 astropy/cosmology/_src/io/connect.py整個(gè)注冊(cè)調(diào)用還會(huì)包在add_enabled_units(cu)上下文中使 astropy 宇宙學(xué)單位如km / (Mpc s)可用。自定義 to/from_format 格式convert_registry官方文檔以astropy.table.Row為例演示了一個(gè)完整的 |Cosmology| ? |Row| 轉(zhuǎn)換器。文檔特意只手寫 mapping 級(jí)別的邏輯而不直接復(fù)用內(nèi)置解析器以便展示最完整的模式。注意真實(shí)的內(nèi)置實(shí)現(xiàn)就在 astropy/cosmology/_src/io/builtin/row.py其from_row的寫法與下面示例幾乎一致同樣是把 Row 轉(zhuǎn)成 dict 后交給from_mapping。1. 編寫 readerRow → Cosmology該函數(shù)應(yīng)接收 1 個(gè)位置參數(shù)行對(duì)象和 2 個(gè)關(guān)鍵字參數(shù)move_to_meta多余字段如何處理與cosmology使用哪個(gè)Cosmology類。關(guān)于元數(shù)據(jù)處理的詳細(xì)說明可以通過Cosmology.from_format.help(mapping)查看。 import copy from astropy.cosmology import Cosmology def from_table_row(row, *, move_to_metaFalse, cosmologyNone): ... # get name from column ... name row[name] if name in row.columns else None ... meta copy.deepcopy(row.meta) ... # turn row into mapping (dict of the arguments) ... mapping dict(row) ... mapping[name] name ... mapping.setdefault(cosmology, meta.pop(cosmology, None)) ... mapping[meta] meta ... # build cosmology from map ... return Cosmology.from_format(mapping, move_to_metamove_to_meta, ... cosmologycosmology)關(guān)鍵設(shè)計(jì)在于reader 并不自己解析每個(gè)物理參數(shù)而是把 Row 拼回一個(gè) mapping再委托給內(nèi)置的mapping格式Cosmology.from_format(mapping, ...)。move_to_meta與cosmology兩個(gè)參數(shù)原樣透?jìng)鞅ＷC行為與內(nèi)置格式一致。對(duì)照內(nèi)置實(shí)現(xiàn) astropy/cosmology/_src/io/builtin/mapping.py 中的from_mapping可以看到其核心邏輯是按rename映射重命名鍵并通過_rename_map保證重命名后的鍵不與原鍵沖突沖突會(huì)拋出ValueError從cosmology參數(shù)或 mapping 中的cosmology字段確定目標(biāo)類字符串會(huì)通過_COSMOLOGY_CLASSES解析為類用inspect.signature(cosmology)bind_partialapply_defaults把類簽名中的默認(rèn)值填進(jìn)來再逐個(gè)綁定 mapping 中出現(xiàn)的參數(shù)——這就是用具體子類解析時(shí)缺失參數(shù)會(huì)被類默認(rèn)值補(bǔ)齊的底層機(jī)制剩余多余參數(shù)若構(gòu)造函數(shù)有**kwargs則收入其中否則在move_to_metaTrue時(shí)合并進(jìn)meta顯式 metadata 優(yōu)先否則拋出TypeError: there are unused parameters ...。然后注冊(cè)到convert_registry convert_registry.register_reader(astropy.row, Cosmology, from_table_row)2. 編寫 writerCosmology → Rowwriter 只需要Cosmology對(duì)象和一個(gè)*args用來吸收astropy.io.registry.UnifiedReadWriteCosmology.to_format的底層實(shí)現(xiàn)見 connect.py傳遞的多余信息 from astropy.table import QTable def to_table_row(cosmology, *args): ... p cosmology.to_format(mapping, cosmology_as_strTrue) ... meta p.pop(meta) ... # package parameters into lists for Table parsing ... params {k: [v] for k, v in p.items()} ... return QTable(params, metameta)[0] # return row convert_registry.register_writer(astropy.row, Cosmology, to_table_row)兩個(gè)細(xì)節(jié)值得注意to_format(mapping, cosmology_as_strTrue)會(huì)把類對(duì)象換成類名如FlatLambdaCDM使輸出可以放進(jìn) Table 的str13列。參數(shù)語(yǔ)義可對(duì)照 mapping.py 中to_mapping的文檔所有參數(shù)值被包進(jìn)單元素列表{k: [v] for ...}因?yàn)?Table 列必須是序列最后用QTable(...)[0]取出第一行即Row。這與內(nèi)置to_rowbuiltin/row.py內(nèi)部調(diào)to_table后返回table[0]的路徑一致。3. 編寫 identifier 并注冊(cè)identifier 用于在用戶不指定format時(shí)自動(dòng)識(shí)別格式。簽名是(origin, format, *args, **kwargs)origin為read或write對(duì)convert_registry而言待識(shí)別對(duì)象位于args[1]args[0]是目標(biāo)類 from astropy.cosmology import Cosmology from astropy.table import Row def row_identify(origin, format, *args, **kwargs): ... Identify if object uses the Table format. ... if origin read: ... return isinstance(args[1], Row) and (format in (None, astropy.row)) ... return False convert_registry.register_identifier(astropy.row, Cosmology, row_identify)4. 回環(huán)驗(yàn)證注冊(cè)完成后即可在Cosmology.from_format/Cosmology.to_format中使用 from astropy.cosmology import Planck18 row Planck18.to_format(astropy.row) row Row index0 cosmology name H0 Om0 Tcmb0 Neff m_nu Ob0 km / (Mpc s) K eV str13 str8 float64 float64 float64 float64 float64[3] float64 ------------- -------- ------------ ------- ------- ------- ----------- ------- FlatLambdaCDM Planck18 67.66 0.30966 2.7255 3.046 0.0 .. 0.06 0.04897 cosmo Cosmology.from_format(row) cosmo Planck18 # test it round-trips Truecosmo Planck18為True說明整個(gè)往返鏈路Cosmology → mapping → QTable/Row → mapping → Cosmology無信息丟失。測(cè)試目錄 astropy/cosmology/_src/tests/io/ 中對(duì)內(nèi)置 row 格式也有等價(jià)的回環(huán)測(cè)試可以參考。自定義 read/write 文件格式readwrite_registry文件級(jí)格式與對(duì)象級(jí)格式的區(qū)別在于reader 接收文件路徑或文件對(duì)象writer 負(fù)責(zé)落盤。官方文檔給出了一個(gè)完整的 |Cosmology| ? JSON 序列化器示例并且復(fù)用已注冊(cè)的 mapping 格式來大幅簡(jiǎn)化實(shí)現(xiàn)——這是推薦做法。1. 編寫 readerJSON → Cosmology函數(shù)接收 1 個(gè)位置參數(shù)文件對(duì)象或文件路徑其余**kwargs透?jìng)鹘oCosmology.from_format由它處理元數(shù)據(jù)和目標(biāo)Cosmology類細(xì)節(jié)同Cosmology.from_format.help(mapping) import json, os import astropy.units as u from astropy.cosmology import Cosmology from astropy.cosmology.io import readwrite_registry def read_json(filename, **kwargs): ... # read file, from path-like or file-like ... if isinstance(filename, (str, bytes, os.PathLike)): ... with open(filename, r) as file: ... data file.read() ... else: # file-like : this also handles errors in dumping ... data filename.read() ... mapping json.loads(data) # parse json mappable to dict ... # deserialize Quantity ... for k, v in mapping.items(): ... if isinstance(v, dict) and value in v and unit in v: ... mapping[k] u.Quantity(v[value], v[unit]) ... for k, v in mapping.get(meta, {}).items(): # also the metadata ... if isinstance(v, dict) and value in v and unit in v: ... mapping[meta][k] u.Quantity(v[value], v[unit]) ... return Cosmology.from_format(mapping, **kwargs) readwrite_registry.register_reader(json, Cosmology, read_json)這段代碼的三個(gè)要點(diǎn)兼容路徑與文件對(duì)象兩種輸入文件對(duì)象分支的注釋指出它順便處理寫出時(shí) dump 的錯(cuò)誤u.Quantity不兼容原生 JSON反序列化約定為{value: ..., unit: ...}結(jié)構(gòu)主參數(shù)和meta中的 Quantity 都要還原解析出 dict 后不再自行構(gòu)造Cosmology而是交給Cosmology.from_format(mapping, **kwargs)——**kwargs中的cosmology/move_to_meta/rename等參數(shù)由 mapping 格式統(tǒng)一處理。2. 編寫 writerCosmology → JSONwriter 需要Cosmology對(duì)象與文件對(duì)象/路徑并需要一個(gè)布爾標(biāo)志overwrite來定義覆蓋已有文件的行為 def write_json(cosmology, file, *, overwriteFalse, **kwargs): ... data cosmology.to_format(mapping, cosmology_as_strTrue) # start by turning into dict ... # serialize Quantity ... for k, v in data.items(): ... if isinstance(v, u.Quantity): ... data[k] {value: v.value.tolist(), unit: str(v.unit)} ... for k, v in data.get(meta, {}).items(): # also serialize the metadata ... if isinstance(v, u.Quantity): ... data[meta][k] {value: v.value.tolist(), unit: str(v.unit)} ... ... if isinstance(file, (str, bytes, os.PathLike)): ... # check that file exists and whether to overwrite. ... if os.path.exists(file) and not overwrite: ... raise IOError(f{file} exists. Set overwrite to write over.) ... with open(file, w) as write_file: ... json.dump(data, write_file) ... else: ... json.dump(data, file) readwrite_registry.register_writer(json, Cosmology, write_json)注意v.value.tolist()把 ndarray 轉(zhuǎn)成純 Python 列表避免json.dump對(duì) numpy 類型報(bào)錯(cuò)overwriteFalse默認(rèn)時(shí)若文件已存在則拋錯(cuò)這是文件級(jí) writer 的常見契約。倉(cāng)庫(kù)中有一份與文檔示例幾乎同構(gòu)、且在 CI 中持續(xù)運(yùn)行的實(shí)現(xiàn)——單元測(cè)試 astropy/cosmology/_src/tests/io/test_json.py它的read_json/write_json/json_identify三個(gè)函數(shù)與文檔示例一一對(duì)應(yīng)測(cè)試版用Path與OSError并把 Quantity 解析包進(jìn)u.add_enabled_units(cu.redshift)上下文以支持紅移單位還額外驗(yàn)證了用寫入時(shí)同一子類讀取部分信息文件時(shí)缺失參數(shù)會(huì)由類默認(rèn)值補(bǔ)齊test_readwrite_json_subclass_partial_info。這可以作為自己實(shí)現(xiàn)文件級(jí)格式時(shí)的參考模板。3. identifier 與回環(huán)驗(yàn)證 def json_identify(origin, filepath, fileobj, *args, **kwargs): ... Identify if object uses the JSON format. ... return filepath is not None and filepath.endswith(.json) readwrite_registry.register_identifier(json, Cosmology, json_identify)文件級(jí) identifier 的簽名是(origin, filepath, fileobj, *args, **kwargs)按 astropy/io/registry/base.py 中register_identifier的說明filepath與fileobj任一可能為None兩者都為None時(shí) identifier 只能依賴args。按文件擴(kuò)展名判斷是最簡(jiǎn)單的可靠策略。注冊(cè)后即可完成文件級(jí)讀寫回環(huán) import tempfile from astropy.cosmology import Planck18 file tempfile.NamedTemporaryFile() Planck18.write(file.name, formatjson, overwriteTrue) with open(file.name) as f: f.readlines() [{cosmology: FlatLambdaCDM, name: Planck18, H0: {value: 67.66, unit: km / (Mpc s)}, Om0: 0.30966, ... cosmo Cosmology.read(file.name, formatjson) file.close() cosmo Planck18 # test it round-trips True輸出的 JSON 中可以看到cosmology以字符串類名出現(xiàn)、H0被展開為{value: 67.66, unit: km / (Mpc s)}與 writer 的序列化約定完全對(duì)應(yīng)。注冊(cè)表 API 細(xì)節(jié)與清理注冊(cè)與解除注冊(cè)從 astropy/io/registry/core.py 可以看到register_reader/register_writer的完整簽名registry.register_reader(data_format, data_class, function, forceFalse, priority0) registry.register_writer(data_format, data_class, function, forceFalse, priority0) registry.register_identifier(data_format, data_class, identifier, forceFalse) # base.py L213重復(fù)注冊(cè)同一(format, class)組合且forceFalse時(shí)會(huì)拋出IORegistryErroralready definedpriority用于在多個(gè)候選格式都匹配時(shí)擇優(yōu)數(shù)值越高越優(yōu)先unregister_reader/unregister_writer/unregister_identifier用于移除注冊(cè)若格式不存在同樣拋IORegistryErrorget_reader(format, class)可查詢當(dāng)前注冊(cè)的函數(shù)未命中時(shí)錯(cuò)誤信息中會(huì)附帶該類的可用格式表_get_format_table_str。官方文檔示例在結(jié)尾特意清理了注冊(cè)狀態(tài)避免示例污染 doctest 環(huán)境 from astropy.io.registry import IORegistryError readwrite_registry.unregister_reader(json, Cosmology) readwrite_registry.unregister_writer(json, Cosmology) readwrite_registry.unregister_identifier(json, Cosmology) try: ... readwrite_registry.get_reader(json, Cosmology) ... except IORegistryError: ... pass這一注冊(cè)—測(cè)試—注銷的三段式與 test_json.py 中 fixture 的 setup/teardown 寫法注冊(cè)時(shí)加forceTrueyield后逐一unregister_*一致是寫測(cè)試時(shí)的最佳實(shí)踐。查看可用格式注冊(cè)表會(huì)把注冊(cè)結(jié)果反映到方法的help()與list_formats()中。當(dāng)前內(nèi)置格式摘自 docs/cosmology/io/index.rst Cosmology.read.list_formats() Format Read Write Auto-identify ---------- ---- ----- ------------- ascii.ecsv Yes Yes Yes ascii.html Yes Yes Yes ascii.mrt Yes Yes Yes Cosmology.write.list_formats() Format Read Write Auto-identify ----------- ---- ----- ------------- ascii.ecsv Yes Yes Yes ascii.html Yes Yes Yes ascii.latex No Yes Yes ascii.mrt Yes Yes Yes Cosmology.to_format.list_formats() Format Read Write Auto-identify ----------------- ---- ----- ------------- astropy.cosmology Yes Yes Yes astropy.model Yes Yes Yes astropy.row Yes Yes Yes astropy.table Yes Yes Yes mapping Yes Yes Yes yaml Yes Yes NoAuto-identify 列即為是否注冊(cè)了 identifier如yaml只有 Yes/Yes/No說明它必須顯式傳formatyaml。你注冊(cè)的第三方格式會(huì)同樣出現(xiàn)在這兩張表中。實(shí)踐要點(diǎn)小結(jié)先想好復(fù)用哪一層能用內(nèi)置mapping格式做膠水的就不要直接手寫參數(shù)解析——兩個(gè)官方示例Row、JSON都是這樣實(shí)現(xiàn)的行為自動(dòng)與move_to_meta、cosmology、rename等語(yǔ)義保持一致兩套注冊(cè)表不要混用對(duì)象級(jí)格式注冊(cè)到convert_registryCosmology.from_format.registry文件級(jí)格式注冊(cè)到readwrite_registryCosmology.read.registry注冊(cè)錯(cuò)表會(huì)導(dǎo)致list_formats中出現(xiàn)卻調(diào)不到identifier 決定自動(dòng)識(shí)別能力文件級(jí)建議用擴(kuò)展名等強(qiáng)信號(hào)JSON 例對(duì)象級(jí)建議用isinstance判斷Row 例并在format已顯式指定時(shí)放行Quantity 需要自定義編解碼u.Quantity與 JSON 等文本格式不兼容{value: ..., unit: ...}約定 遍歷meta是兩個(gè)官方示例共同采用的方案以回環(huán)斷言收尾Cosmology.from_format(cosmo.to_format(...)) cosmo或文件級(jí)的Cosmology.read是驗(yàn)證實(shí)現(xiàn)正確性的最簡(jiǎn)方式官方示例與 astropy/cosmology/_src/tests/io/ 下的測(cè)試均以此為標(biāo)準(zhǔn)動(dòng)作。更多背景I/O 總覽見 docs/cosmology/io/index.rst內(nèi)置格式ascii.ecsv、astropy.table、mapping、yaml等的參數(shù)細(xì)節(jié)見 docs/cosmology/io/builtin.rst字段重命名與子類讀取行為見 docs/cosmology/io/details.rst通用 I/O 注冊(cè)框架見 docs/io/registry.rst。贊分享科學(xué)計(jì)算科研數(shù)據(jù)分析【免費(fèi)下載鏈接】astropyAstronomy and astrophysics core library項(xiàng)目地址https://gitcode.com/gh_mirrors/as/astropy點(diǎn)擊查看免費(fèi)下載相關(guān)推薦astropy Cosmology 內(nèi)置 I/O 格式詳解Cosmology 對(duì)象的轉(zhuǎn)換、讀寫與源碼實(shí)現(xiàn)astropy Cosmology 內(nèi)置 I/O 格式詳解Cosmology 對(duì)象的轉(zhuǎn)換、讀寫與源碼實(shí)現(xiàn) 本文基于 astropy 官方文檔 Built in科學(xué)計(jì)算科研數(shù)據(jù)分析astropy 宇宙學(xué)模塊開發(fā)者指南default_cosmology、自定義 Cosmology 與 I/O 互操作astropy 宇宙學(xué)模塊開發(fā)者指南default_cosmology、自定義 Cosmology 與 I/O 互操作 本文基于 astropy 官方開發(fā)者文科學(xué)計(jì)算科研數(shù)據(jù)分析網(wǎng)頁(yè)視頻怎么下載貓抓從資源嗅探到 M3U8 合并的 3 步完整流程網(wǎng)頁(yè)視頻怎么下載貓抓從資源嗅探到 M3U8 合并的 3 步完整流程 貓抓cat catch是一款瀏覽器資源嗅探擴(kuò)展打開網(wǎng)頁(yè)后自動(dòng)列出其中的 MP4、M3音視頻上一篇Dear ImGui 自寫渲染后端如何支持 ImGuiBackendFlags_RendererHasTextures1.92下一篇Gin 開啟 HTTP/2 服務(wù)推送RunTLS 環(huán)境下怎么用 Writer.Pusher 預(yù)推靜態(tài)資源創(chuàng)作聲明：本文部分內(nèi)容由AI輔助生成（AIGC），僅供參考