<!DOCTYPE HTML>
< html lang = "zh-CN" class = "sidebar-visible no-js light" >
< head >
<!-- Book generated using mdBook -->
< meta charset = "UTF-8" >
< title > CSV - Rusty Book(锈书)< / title >
<!-- Custom HTML head -->
< meta content = "text/html; charset=utf-8" http-equiv = "Content-Type" >
< meta name = "description" content = "" >
< meta name = "viewport" content = "width=device-width, initial-scale=1" >
< meta name = "theme-color" content = "#ffffff" / >
< link rel = "icon" href = "../favicon.svg" >
< link rel = "shortcut icon" href = "../favicon.png" >
< link rel = "stylesheet" href = "../css/variables.css" >
< link rel = "stylesheet" href = "../css/general.css" >
< link rel = "stylesheet" href = "../css/chrome.css" >
< link rel = "stylesheet" href = "../css/print.css" media = "print" >
<!-- Fonts -->
< link rel = "stylesheet" href = "../FontAwesome/css/font-awesome.css" >
< link rel = "stylesheet" href = "../fonts/fonts.css" >
<!-- Highlight.js Stylesheets -->
< link rel = "stylesheet" href = "../highlight.css" >
< link rel = "stylesheet" href = "../tomorrow-night.css" >
< link rel = "stylesheet" href = "../ayu-highlight.css" >
<!-- Custom theme stylesheets -->
< link rel = "stylesheet" href = "../theme/style1.css" >
< / head >
< body >
<!-- Provide site root to javascript -->
< script type = "text/javascript" >
var path_to_root = "../";
var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
< / script >
<!-- Work around some values being stored in localStorage wrapped in quotes -->
< script type = "text/javascript" >
try {
var theme = localStorage.getItem('mdbook-theme');
var sidebar = localStorage.getItem('mdbook-sidebar');
if (theme.startsWith('"') & & theme.endsWith('"')) {
localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
}
if (sidebar.startsWith('"') & & sidebar.endsWith('"')) {
localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
}
} catch (e) { }
< / script >
<!-- Set the theme before any content is loaded, prevents flash -->
< script type = "text/javascript" >
var theme;
try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
if (theme === null || theme === undefined) { theme = default_theme; }
var html = document.querySelector('html');
html.classList.remove('no-js')
html.classList.remove('light')
html.classList.add(theme);
html.classList.add('js');
< / script >
<!-- Hide / unhide sidebar before it is displayed -->
< script type = "text/javascript" >
var html = document.querySelector('html');
var sidebar = 'hidden';
if (document.body.clientWidth >= 1080) {
try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
sidebar = sidebar || 'visible';
}
html.classList.remove('sidebar-visible');
html.classList.add("sidebar-" + sidebar);
< / script >
< nav id = "sidebar" class = "sidebar" aria-label = "Table of contents" >
< div class = "sidebar-scrollbox" >
< ol class = "chapter" > < li class = "chapter-item expanded affix " > < a href = "../about.html" > Rusty Book< / a > < / li > < li class = "chapter-item expanded affix " > < li class = "part-title" > Awesome< / li > < li class = "spacer" > < / li > < li class = "chapter-item expanded " > < a href = "../daily-dev.html" > 日常开发常用库< / a > < / li > < li class = "chapter-item expanded " > < a href = "../superstar.html" > Rust 明星项目< / a > < / li > < li class = "chapter-item expanded " > < a href = "../empowering-js.html" > 使用 Rust 增强 JS< / a > < / li > < li class = "chapter-item expanded " > < a href = "../games.html" > Rust开发的游戏< / a > < / li > < li class = "chapter-item expanded " > < a href = "../gamedev.html" > 游戏引擎< / a > < / li > < li class = "chapter-item expanded affix " > < li class = "part-title" > Awesome + Cookbook< / li > < li class = "spacer" > < / li > < li class = "chapter-item expanded " > < a href = "../algos/awesome.html" > 实用算法< / a > < a class = "toggle" > < div > ❱< / div > < / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "../algos/randomness.html" > 生成随机值< / a > < / li > < li class = "chapter-item expanded " > < a href = "../algos/sorting.html" > Vec 排序< / a > < / li > < li class = "chapter-item expanded " > < div > 压缩算法< / div > < a class = "toggle" > < div > ❱< / div > < / a > < / li > < li > < ol class = "section" > < li class = "chapter-item " > < a href = "../algos/compression/tar.html" > 使用.tar包< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < div > 密码学< / div > < a class = "toggle" > < div > ❱< / div > < / a > < / li > < li > < ol class = "section" > < li class = "chapter-item " > < a href = "../algos/cryptography/hashing.html" > 哈希< / a > < / li > < li class = "chapter-item " > < a href = "../algos/cryptography/encryption.html" > 加密< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < div > 数学计算< / div > < a class = "toggle" > < div > ❱< / div > < / a > < / li > < li > < ol class = "section" > < li class = "chapter-item " > < a href = "../algos/math/linear-algebra.html" > 线性代数< / a > < / li > < li class = "chapter-item " > < a href = "../algos/math/trigonometry.html" > 三角函数< / a > < / li > < li class = "chapter-item " > < a href = "../algos/math/complex.html" > 复数< / a > < / li > < li class = "chapter-item " > < a href = "../algos/math/statistics.html" > 统计学< / a > < / li > < li class = "chapter-item " > < a href = "../algos/math/misc.html" > 杂项< / a > < / li > < / ol > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < a href = "../datastructures/awesome.html" > 数据结构< / a > < a class = "toggle" > < div > ❱< / div > < / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "../datastructures/bitfield.html" > 位字段< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < a href = "../cmd/awesome.html" > 命令行< / a > < a class = "toggle" > < div > ❱< / div > < / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "../cmd/parsing.html" > 参数解析< / a > < / li > < li class = "chapter-item expanded " > < a href = "../cmd/ansi.html" > 终端输出格式化< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < a href = "../os/awesome.html" > 操作系统< / a > < a class = "toggle" > < div > ❱< / div > < / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "../os/processor.html" > 处理器< / a > < / li > < li class = "chapter-item expanded " > < a href = "../os/command.html" > 调用系统命令< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < div > 并发< / div > < a class = "toggle" > < div > ❱< / div > < / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "../cocurrency/threads.html" > 线程< / a > < / li > < li class = "chapter-item expanded " > < a href = "../cocurrency/parallel.html" > 使用rayon并行处理数据< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < div > 数据库< / div > < a class = "toggle" > < div > ❱< / div > < / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "../database/sqlite.html" > SQLite< / a > < / li > < li class = "chapter-item expanded " > < a href = "../database/postgres.html" > Postgres< / a > < / li > < / ol > < / li > < li class = "chapter-item expanded " > < div > 日期和时间< / div > < a class = "toggle" > < div > ❱< / div > < / a > < / li > < li > < ol class = "section" > < li class = "chapter-item expanded " > < a href = "../datetime/duration.html" > 时间计算和转换< / a > < / li > < li class = "chapter-item expanded " > < a href = "../datetime/parsing.html" > 解析和显示< / a > < / li > < / ol > < / li > < li class = "chapter-it
< / div >
< div id = "sidebar-resize-handle" class = "sidebar-resize-handle" > < / div >
< / nav >
< div id = "page-wrapper" class = "page-wrapper" >
< div class = "page" >
< div id = "menu-bar-hover-placeholder" > < / div >
< div id = "menu-bar" class = "menu-bar sticky bordered" >
< div class = "left-buttons" >
< button id = "sidebar-toggle" class = "icon-button" type = "button" title = "Toggle Table of Contents" aria-label = "Toggle Table of Contents" aria-controls = "sidebar" >
< i class = "fa fa-bars" > < / i >
< / button >
< button id = "theme-toggle" class = "icon-button" type = "button" title = "Change theme" aria-label = "Change theme" aria-haspopup = "true" aria-expanded = "false" aria-controls = "theme-list" >
< i class = "fa fa-paint-brush" > < / i >
< / button >
< ul id = "theme-list" class = "theme-popup" aria-label = "Themes" role = "menu" >
< li role = "none" > < button role = "menuitem" class = "theme" id = "light" > Light (default)< / button > < / li >
< li role = "none" > < button role = "menuitem" class = "theme" id = "rust" > Rust< / button > < / li >
< li role = "none" > < button role = "menuitem" class = "theme" id = "coal" > Coal< / button > < / li >
< li role = "none" > < button role = "menuitem" class = "theme" id = "navy" > Navy< / button > < / li >
< li role = "none" > < button role = "menuitem" class = "theme" id = "ayu" > Ayu< / button > < / li >
< / ul >
< button id = "search-toggle" class = "icon-button" type = "button" title = "Search. (Shortkey: s)" aria-label = "Toggle Searchbar" aria-expanded = "false" aria-keyshortcuts = "S" aria-controls = "searchbar" >
< i class = "fa fa-search" > < / i >
< / button >
< / div >
< h1 class = "menu-title" > Rusty Book(锈书)< / h1 >
< div class = "right-buttons" >
< a href = "../print.html" title = "Print this book" aria-label = "Print this book" >
< i id = "print-button" class = "fa fa-print" > < / i >
< / a >
< a href = "https://github.com/studyrs/rusty-book" title = "Git repository" aria-label = "Git repository" >
< i id = "git-repository-button" class = "fa fa-github" > < / i >
< / a >
< a href = "https://github.com/studyrs/rusty-book/edit/main/src/encoding/csv.md" title = "Suggest an edit" aria-label = "Suggest an edit" >
< i id = "git-edit-button" class = "fa fa-edit" > < / i >
< / a >
< / div >
< / div >
< div id = "search-wrapper" class = "hidden" >
< form id = "searchbar-outer" class = "searchbar-outer" >
< input type = "search" id = "searchbar" name = "searchbar" placeholder = "Search this book ..." aria-controls = "searchresults-outer" aria-describedby = "searchresults-header" >
< / form >
< div id = "searchresults-outer" class = "searchresults-outer hidden" >
< div id = "searchresults-header" class = "searchresults-header" > < / div >
< ul id = "searchresults" >
< / ul >
< / div >
< / div >
<!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
< script type = "text/javascript" >
document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
});
< / script >
< div id = "content" class = "content" >
<!-- Page table of contents -->
< div class = "sidetoc" > < nav class = "pagetoc" > < / nav > < / div >
< main >
< h1 id = "csv" > < a class = "header" href = "#csv" > CSV< / a > < / h1 >
< h2 id = "读取-csv-记录" > < a class = "header" href = "#读取-csv-记录" > 读取 CSV 记录< / a > < / h2 >
< p > 我们可以将标准的 CSV 记录值读取到 < a href = "https://docs.rs/csv/*/csv/struct.StringRecord.html" > csv::StringRecord< / a > 中，但是该数据结构期待合法的 UTF8 数据行，你还可以使用 < a href = "https://docs.rs/csv/1.1.6/csv/struct.ByteRecord.html" > csv::ByteRecord< / a > 来读取非 UTF8 数据。< / p >
< pre > < pre class = "playground" > < code class = "language-rust editable edition2021" > use csv::Error;
fn main() -> Result< (), Error> {
let csv = " year,make,model,description
1948,Porsche,356,Luxury sports car
1967,Ford,Mustang fastback 1967,American car" ;
let mut reader = csv::Reader::from_reader(csv.as_bytes());
for record in reader.records() {
let record = record?;
println!(
" In {}, {} built the {} model. It is a {}." ,
& record[0],
& record[1],
& record[2],
& record[3]
);
}
Ok(())
}
< / code > < / pre > < / pre >
< p > 还可以使用 < a href = "https://docs.rs/serde/1.0.136/serde/" > < code > serde< / code > < / a > 将数据反序列化成一个强类型的结构体。< / p >
< pre > < pre class = "playground" > < code class = "language-rust editable edition2021" > use serde::Deserialize;
#[derive(Deserialize)]
struct Record {
year: u16,
make: String,
model: String,
description: String,
}
fn main() -> Result< (), csv::Error> {
let csv = " year,make,model,description
1948,Porsche,356,Luxury sports car
1967,Ford,Mustang fastback 1967,American car" ;
let mut reader = csv::Reader::from_reader(csv.as_bytes());
for record in reader.deserialize() {
let record: Record = record?;
println!(
" In {}, {} built the {} model. It is a {}." ,
record.year,
record.make,
record.model,
record.description
);
}
Ok(())
}
< / code > < / pre > < / pre >
< h3 id = "读取使用了不同分隔符的-csv-记录" > < a class = "header" href = "#读取使用了不同分隔符的-csv-记录" > 读取使用了不同分隔符的 CSV 记录< / a > < / h3 >
< p > 下面的例子将读取使用了 < code > tab< / code > 作为分隔符的 CSV 记录。< / p >
< pre > < pre class = "playground" > < code class = "language-rust editable edition2021" > use csv::Error;
use serde::Deserialize;
#[derive(Debug, Deserialize)]
struct Record {
name: String,
place: String,
#[serde(deserialize_with = " csv::invalid_option" )]
id: Option< u64> ,
}
use csv::ReaderBuilder;
fn main() -> Result< (), Error> {
let data = " name\tplace\tid
Mark\tMelbourne\t46
Ashley\tZurich\t92" ;
let mut reader = ReaderBuilder::new().delimiter(b'\t').from_reader(data.as_bytes());
for result in reader.deserialize::< Record> () {
println!(" {:?}" , result?);
}
Ok(())
}
< / code > < / pre > < / pre >
< h3 id = "基于给定条件来过滤-csv-记录" > < a class = "header" href = "#基于给定条件来过滤-csv-记录" > 基于给定条件来过滤 CSV 记录< / a > < / h3 >
< pre > < pre class = "playground" > < code class = "language-rust editable edition2021" > use error_chain::error_chain;
use std::io;
error_chain!{
foreign_links {
Io(std::io::Error);
CsvError(csv::Error);
}
}
fn main() -> Result< ()> {
let query = " CA" ;
let data = " \
City,State,Population,Latitude,Longitude
Kenai,AK,7610,60.5544444,-151.2583333
Oakman,AL,,33.7133333,-87.3886111
Sandfort,AL,,32.3380556,-85.2233333
West Hollywood,CA,37031,34.0900000,-118.3608333" ;
let mut rdr = csv::ReaderBuilder::new().from_reader(data.as_bytes());
let mut wtr = csv::Writer::from_writer(io::stdout());
wtr.write_record(rdr.headers()?)?;
for result in rdr.records() {
let record = result?;
if record.iter().any(|field| field == query) {
wtr.write_record(& record)?;
}
}
wtr.flush()?;
Ok(())
}
< / code > < / pre > < / pre >
< h3 id = "序列化为-csv" > < a class = "header" href = "#序列化为-csv" > 序列化为 CSV< / a > < / h3 >
< p > 下面例子展示了如何将 Rust 类型序列化为 CSV。< / p >
< pre > < pre class = "playground" > < code class = "language-rust editable edition2021" > use std::io;
fn main() -> Result< ()> {
let mut wtr = csv::Writer::from_writer(io::stdout());
wtr.write_record(& [" Name" , " Place" , " ID" ])?;
wtr.serialize((" Mark" , " Sydney" , 87))?;
wtr.serialize((" Ashley" , " Dublin" , 32))?;
wtr.serialize((" Akshat" , " Delhi" , 11))?;
wtr.flush()?;
Ok(())
}
< / code > < / pre > < / pre >
< h3 id = "使用-serde-序列化为-csv" > < a class = "header" href = "#使用-serde-序列化为-csv" > 使用 serde 序列化为 CSV< / a > < / h3 >
< p > 下面例子将自定义数据结构通过 < code > serde< / code > 序列化 CSV。< / p >
< pre > < pre class = "playground" > < code class = "language-rust editable edition2021" > use error_chain::error_chain;
use serde::Serialize;
use std::io;
error_chain! {
foreign_links {
IOError(std::io::Error);
CSVError(csv::Error);
}
}
#[derive(Serialize)]
struct Record< 'a> {
name: & 'a str,
place: & 'a str,
id: u64,
}
fn main() -> Result< ()> {
let mut wtr = csv::Writer::from_writer(io::stdout());
let rec1 = Record { name: " Mark" , place: " Melbourne" , id: 56};
let rec2 = Record { name: " Ashley" , place: " Sydney" , id: 64};
let rec3 = Record { name: " Akshat" , place: " Delhi" , id: 98};
wtr.serialize(rec1)?;
wtr.serialize(rec2)?;
wtr.serialize(rec3)?;
wtr.flush()?;
Ok(())
}
< / code > < / pre > < / pre >
< h3 id = "csv-列转换" > < a class = "header" href = "#csv-列转换" > CSV 列转换< / a > < / h3 >
< p > 下面代码将包含有颜色名和十六进制颜色的 CSV 文件转换为包含颜色名和 rgb 颜色。这里使用 < code > csv< / code > 包对 CSV 文件进行读写，然后用 < code > serde< / code > 进行序列化和反序列化。< / p >
< pre > < pre class = "playground" > < code class = "language-rust editable edition2021" > < span class = "boring" > use error_chain::error_chain;
< / span > use csv::{Reader, Writer};
use serde::{de, Deserialize, Deserializer};
use std::str::FromStr;
< span class = "boring" > error_chain! {
< / span > < span class = "boring" > foreign_links {
< / span > < span class = "boring" > CsvError(csv::Error);
< / span > < span class = "boring" > ParseInt(std::num::ParseIntError);
< / span > < span class = "boring" > CsvInnerError(csv::IntoInnerError< Writer< Vec< u8> > > );
< / span > < span class = "boring" > IO(std::fmt::Error);
< / span > < span class = "boring" > UTF8(std::string::FromUtf8Error);
< / span > < span class = "boring" > }
< / span > < span class = "boring" > }
< / span >
#[derive(Debug)]
struct HexColor {
red: u8,
green: u8,
blue: u8,
}
#[derive(Debug, Deserialize)]
struct Row {
color_name: String,
color: HexColor,
}
impl FromStr for HexColor {
type Err = Error;
fn from_str(hex_color: & str) -> std::result::Result< Self, Self::Err> {
let trimmed = hex_color.trim_matches('#');
if trimmed.len() != 6 {
Err(" Invalid length of hex string" .into())
} else {
Ok(HexColor {
red: u8::from_str_radix(& trimmed[..2], 16)?,
green: u8::from_str_radix(& trimmed[2..4], 16)?,
blue: u8::from_str_radix(& trimmed[4..6], 16)?,
})
}
}
}
impl< 'de> Deserialize< 'de> for HexColor {
fn deserialize< D> (deserializer: D) -> std::result::Result< Self, D::Error>
where
D: Deserializer< 'de> ,
{
let s = String::deserialize(deserializer)?;
FromStr::from_str(& s).map_err(de::Error::custom)
}
}
fn main() -> Result< ()> {
let data = " color_name,color
red,#ff0000
green,#00ff00
blue,#0000FF
periwinkle,#ccccff
magenta,#ff00ff"
.to_owned();
let mut out = Writer::from_writer(vec![]);
let mut reader = Reader::from_reader(data.as_bytes());
for result in reader.deserialize::< Row> () {
let res = result?;
out.serialize((
res.color_name,
res.color.red,
res.color.green,
res.color.blue,
))?;
}
let written = String::from_utf8(out.into_inner()?)?;
assert_eq!(Some(" magenta,255,0,255" ), written.lines().last());
println!(" {}" , written);
Ok(())
}
< / code > < / pre > < / pre >
< div id = "giscus-container" > < / div >
< / main >
< nav class = "nav-wrapper" aria-label = "Page navigation" >
<!-- Mobile navigation buttons -->
< a rel = "prev" href = "../encoding/strings.html" class = "mobile-nav-chapters previous" title = "Previous chapter" aria-label = "Previous chapter" aria-keyshortcuts = "Left" >
< i class = "fa fa-angle-left" > < / i >
< / a >
< a rel = "next" href = "../encoding/structured.html" class = "mobile-nav-chapters next" title = "Next chapter" aria-label = "Next chapter" aria-keyshortcuts = "Right" >
< i class = "fa fa-angle-right" > < / i >
< / a >
< div style = "clear: both" > < / div >
< / nav >
< / div >
< / div >
< nav class = "nav-wide-wrapper" aria-label = "Page navigation" >
< a rel = "prev" href = "../encoding/strings.html" class = "nav-chapters previous" title = "Previous chapter" aria-label = "Previous chapter" aria-keyshortcuts = "Left" >
< i class = "fa fa-angle-left" > < / i >
< / a >
< a rel = "next" href = "../encoding/structured.html" class = "nav-chapters next" title = "Next chapter" aria-label = "Next chapter" aria-keyshortcuts = "Right" >
< i class = "fa fa-angle-right" > < / i >
< / a >
< / nav >
< / div >
< script type = "text/javascript" >
window.playground_copyable = true;
< / script >
< script src = "../ace.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "../editor.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "../mode-rust.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "../theme-dawn.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "../theme-tomorrow_night.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "../elasticlunr.min.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "../mark.min.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "../searcher.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "../clipboard.min.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "../highlight.js" type = "text/javascript" charset = "utf-8" > < / script >
< script src = "../book.js" type = "text/javascript" charset = "utf-8" > < / script >
< script type = "text/javascript" charset = "utf-8" >
var pagePath = "encoding/csv.md"
< / script >
<!-- Custom JS scripts -->
< script type = "text/javascript" src = "../assets/custom1.js" > < / script >
< script type = "text/javascript" src = "../assets/bigPicture.js" > < / script >
< / body >
< / html >
