Rust : 读含有中文字符的CSV文件解决方案

本文感谢42的帮助。

Rust有一个库CSV，可以用来处理相关的CSV文件。

相关资料见：http://burntsushi.net/rustdoc/csv/

比如有个CSV文件,其结构是（有表头的）：

以下读出CSV,可以有两种组织方式：

一、可以解析成tuple.

extern crate stopwatch;
extern crate csv;
fn main() {

let mut rdr =
        csv::Reader::from_file("C:\\IC1505.csv").unwrap().has_headers(false);//不要求是读出第一行段首，否则选择true.
    for record in rdr.decode() {
let (s1, s2, dist): (String, String, String) = record.unwrap();
        println!("{}=> {}, {}, {}", num, s1, s2, dist);
    }
thread::sleep_ms(500000);
}

二、也可以解析成struct，非常方便，赞！

extern crate stopwatch;
extern crate csv;
extern crate rustc_serialize;
use stopwatch::Stopwatch;
use std::thread;
#[derive(RustcDecodable, RustcEncodable)]
struct bar {
    market: String,
    code: String,
    date: String,
    open: String,//=>f64?
    high: String,//=>f64?
    low: String,//=>f64?
    volume: String,//=>f64?
    openInterests: String,//=>f64?
}
fn main() {
let mut rdr =
        csv::Reader::from_file("C:\\IC1505.csv").unwrap().has_headers(false);
for record in rdr.decode() {
let temp: bar = record.unwrap();
        println!("{}=> {}, {}, {},{},{}",
                 num,
                 temp.market,
                 temp.code,
                 temp.date,
                 temp.open,
                 temp.high);
    }
    thread::sleep_ms(500000);
}

三、关于struct的优化

如何把bar的结构精准地描述（f64,String…..）?
我们发现：
如果去掉表头，形成以下模式，则可以把bar结构中字段进行精确解析。

extern crate stopwatch;
extern crate csv;
extern crate rustc_serialize;
use stopwatch::Stopwatch;
use std::thread;
use std::io;
use std::time::{Duration, Instant};

#[derive(RustcDecodable, RustcEncodable)]
struct bar {
    market: String,
    code: String,
    date: String,
    open: f64,
    high: f64,
    low: f64,
    close: f64,
    volume: f64,
    openInterests: f64,
}
fn main() {
let mut rdr =
        csv::Reader::from_file("C:\\IC1505.csv").unwrap().has_headers(false);
let mut data: Vec<bar> = Vec::new();
for record in rdr.decode() {
let mut temp: bar = record.unwrap();
        println!("len: =>{:?},{},{},{},{}",
                 data.len(),
                 temp.market,
                 temp.code,
                 temp.date,
                 temp.close);
        data.push(temp);
    }
    thread::sleep_ms(500000);
}

四、csv库如何读出汉字？
比如：

extern crate csv;
extern crate rustc_serialize;
extern crate encoding;

use std::io;
use std::io::prelude::*;
use std::fs::File;

use encoding::{Encoding,  DecoderTrap};
use encoding::all::GB18030;//可以转成汉字的字库

fn main() {
let path = "C:\\Users\\Desktop\\test.csv";
let mut f = File::open(path).ok().expect("cannot open file"); 
let mut reader: Vec<u8> = Vec::new();
    f.read_to_end(&mut reader).ok().expect("can not read file");
let mut chars = String::new();
    GB18030.decode_to(&mut reader, DecoderTrap::Ignore, &mut chars);
let mut rdr = csv::Reader::from_string(chars).has_headers(true);
for row in rdr.decode() {
let (x, y, r): (String, String, String) = row.unwrap();
        println!("({}, {}): {:?}", x, y, r);
    }
}