WHO COVID-2019 データを取得するパッケージを作ってみた

package main

import (
    "bytes"
    "fmt"
    "io"
    "os"
    "time"

    "github.com/spiegel-im-spiegel/cov19data"
    "github.com/spiegel-im-spiegel/cov19data/client"
    "github.com/spiegel-im-spiegel/cov19data/filter"
    "github.com/spiegel-im-spiegel/cov19data/histogram"
    "github.com/spiegel-im-spiegel/cov19data/values"
    "github.com/spiegel-im-spiegel/errs"
)

func getHist() ([]*histogram.HistData, error) {
    impt, err := cov19data.NewWeb(client.Default())
    if err != nil {
        return nil, errs.Wrap(err)
    }
    defer impt.Close()
    return impt.Histogram(
        values.NewPeriod(
            values.NewDate(2020, time.Month(9), 1),
            values.NewDate(2020, time.Month(9), 28),
        ),
        7,
        filter.WithCountryCode(values.CC_JP),
        filter.WithRegionCode(values.WPRO),
    )
}

func main() {
    hist, err := getHist()
    if err != nil {
        fmt.Fprintf(os.Stderr, "%+v\n", err)
        return
    }
    b, err := histogram.ExportCSV(hist)
    if err != nil {
        fmt.Fprintf(os.Stderr, "%v\n", err)
        return
    }
    if _, err := io.Copy(os.Stdout, bytes.NewReader(b)); err != nil {
        fmt.Println(err)
    }
    // Output:
    // Date_from,Date_to,Cases,Deaths
    // 2020-09-01,2020-09-07,3991,84
    // 2020-09-08,2020-09-14,3801,79
    // 2020-09-15,2020-09-21,3483,58
    // 2020-09-22,2020-09-28,2991,48
}