世界中の Web API を C# から使う

10年くらい前、「世界中の Web API に自由に接続し、様々なデータを簡単に収集できる時代が来た」と騒がれていた時期がありましたが、最近、会社情報を収集する必要が出て、世界中のWeb API を利用する為のプラットフォームになっている RapidAPI を使ってみたら、そんな時代が来ていることを実感しました。

自分が使ったのは、 Rakuten RapidAPI の中にある、Yahoo Finance API。
アジア向けの RapidAPI サービスは、楽天が請け負っているらしい。
Yahoo Finance API の概要は、Yahoo Finance API – The Complete Guide に記載されている。

料金プランが明瞭。どのAPIも料金プランのレイアウトが同じなのは、混乱しなくて助かる。

Yahoo Finance API は、アップルのような米国会社情報も収集できる。

C#で収集する場合のソースコードも出力してくれる。

RestSharp形式の C#ソースコード実行には、 RestSharp Nugetパッケージのインストールが必要。

後は、Visual Studio のプロジェクトにソースコードを貼り付けて、実行するだけ。

保存したJsonデータは、VisualStudioのドキュメントフォーマットを行うと見易くなる。

保存

before

ドキュメントフォーマット実行

After

保存したJsonデータに対応するClassを作成する際は、「JSONをクラスとして貼り付ける」機能を使用すると便利。JSONデータのフォーマットに対応したデータクラスを自動生成してくれる。

Yahoo Finance API の受信結果をデータクラスに変換する処理はこんな感じ。


using System;
using Newtonsoft.Json;
using RestSharp;


            var client = new RestClient("https://stock-data-yahoo-finance-alternative.p.rapidapi.com/v6/finance/quote?symbols=AAPL%2CMSFT&lang=en&region=US");
            var request = new RestRequest(Method.GET);
            request.AddHeader("x-rapidapi-key", "〇〇〇");
            request.AddHeader("x-rapidapi-host", "□□□");

            var response = client.Execute<YahooFinanceApiResponse>(request);

            var yahooFinanceApiResponse = JsonConvert.DeserializeObject<YahooFinanceApiResponse>(response.Content);

using System;

using Newtonsoft.Json;

using RestSharp;

var client = new RestClient("https://stock-data-yahoo-finance-alternative.p.rapidapi.com/v6/finance/quote?symbols=AAPL%2CMSFT&lang=en&region=US");

var request = new RestRequest(Method.GET);

request.AddHeader("x-rapidapi-key", "〇〇〇");

request.AddHeader("x-rapidapi-host", "□□□");

var response = client.Execute<YahooFinanceApiResponse>(request);

var yahooFinanceApiResponse = JsonConvert.DeserializeObject<YahooFinanceApiResponse>(response.Content);


    public class YahooFinanceApiResponse
    {
        public Quoteresponse quoteResponse { get; set; }
    }

    public class Quoteresponse
    {
        public Result[] result { get; set; }
        public object error { get; set; }
    }

    public class Result
    {
        public string language { get; set; }
        public string region { get; set; }
        public string quoteType { get; set; }
        public string quoteSourceName { get; set; }
        public bool triggerable { get; set; }
        public string currency { get; set; }
        public long firstTradeDateMilliseconds { get; set; }
        public int priceHint { get; set; }
        public float preMarketChange { get; set; }
        public float preMarketChangePercent { get; set; }
        public int preMarketTime { get; set; }
        public float preMarketPrice { get; set; }
        public float regularMarketChange { get; set; }
        public float regularMarketChangePercent { get; set; }
        public int regularMarketTime { get; set; }
        public float regularMarketPrice { get; set; }
        public float regularMarketDayHigh { get; set; }
        public string regularMarketDayRange { get; set; }
        public float regularMarketDayLow { get; set; }
        public int regularMarketVolume { get; set; }
        public float regularMarketPreviousClose { get; set; }
        public float bid { get; set; }
        public float ask { get; set; }
        public int bidSize { get; set; }
        public int askSize { get; set; }
        public string fullExchangeName { get; set; }
        public string financialCurrency { get; set; }
        public float regularMarketOpen { get; set; }
        public int averageDailyVolume3Month { get; set; }
        public int averageDailyVolume10Day { get; set; }
        public float fiftyTwoWeekLowChange { get; set; }
        public float fiftyTwoWeekLowChangePercent { get; set; }
        public string fiftyTwoWeekRange { get; set; }
        public float fiftyTwoWeekHighChange { get; set; }
        public float fiftyTwoWeekHighChangePercent { get; set; }
        public float fiftyTwoWeekLow { get; set; }
        public float fiftyTwoWeekHigh { get; set; }
        public int dividendDate { get; set; }
        public int earningsTimestamp { get; set; }
        public int earningsTimestampStart { get; set; }
        public int earningsTimestampEnd { get; set; }
        public float trailingAnnualDividendRate { get; set; }
        public float trailingPE { get; set; }
        public float trailingAnnualDividendYield { get; set; }
        public float epsTrailingTwelveMonths { get; set; }
        public float epsForward { get; set; }
        public float epsCurrentYear { get; set; }
        public float priceEpsCurrentYear { get; set; }
        public long sharesOutstanding { get; set; }
        public float bookValue { get; set; }
        public float fiftyDayAverage { get; set; }
        public float fiftyDayAverageChange { get; set; }
        public float fiftyDayAverageChangePercent { get; set; }
        public float twoHundredDayAverage { get; set; }
        public float twoHundredDayAverageChange { get; set; }
        public float twoHundredDayAverageChangePercent { get; set; }
        public long marketCap { get; set; }
        public float forwardPE { get; set; }
        public float priceToBook { get; set; }
        public int sourceInterval { get; set; }
        public int exchangeDataDelayedBy { get; set; }
        public string averageAnalystRating { get; set; }
        public bool tradeable { get; set; }
        public string exchange { get; set; }
        public string longName { get; set; }
        public string messageBoardId { get; set; }
        public string exchangeTimezoneName { get; set; }
        public string exchangeTimezoneShortName { get; set; }
        public int gmtOffSetMilliseconds { get; set; }
        public string market { get; set; }
        public bool esgPopulated { get; set; }
        public string shortName { get; set; }
        public string marketState { get; set; }
        public string displayName { get; set; }
        public string symbol { get; set; }
    }

public class YahooFinanceApiResponse

{

public Quoteresponse quoteResponse { get; set; }

}

public class Quoteresponse

{

public Result[] result { get; set; }

public object error { get; set; }

}

public class Result

{

public string language { get; set; }

public string region { get; set; }

public string quoteType { get; set; }

public string quoteSourceName { get; set; }

public bool triggerable { get; set; }

public string currency { get; set; }

public long firstTradeDateMilliseconds { get; set; }

public int priceHint { get; set; }

public float preMarketChange { get; set; }

public float preMarketChangePercent { get; set; }

public int preMarketTime { get; set; }

public float preMarketPrice { get; set; }

public float regularMarketChange { get; set; }

public float regularMarketChangePercent { get; set; }

public int regularMarketTime { get; set; }

public float regularMarketPrice { get; set; }

public float regularMarketDayHigh { get; set; }

public string regularMarketDayRange { get; set; }

public float regularMarketDayLow { get; set; }

public int regularMarketVolume { get; set; }

public float regularMarketPreviousClose { get; set; }

public float bid { get; set; }

public float ask { get; set; }

public int bidSize { get; set; }

public int askSize { get; set; }

public string fullExchangeName { get; set; }

public string financialCurrency { get; set; }

public float regularMarketOpen { get; set; }

public int averageDailyVolume3Month { get; set; }

public int averageDailyVolume10Day { get; set; }

public float fiftyTwoWeekLowChange { get; set; }

public float fiftyTwoWeekLowChangePercent { get; set; }

public string fiftyTwoWeekRange { get; set; }

public float fiftyTwoWeekHighChange { get; set; }

public float fiftyTwoWeekHighChangePercent { get; set; }

public float fiftyTwoWeekLow { get; set; }

public float fiftyTwoWeekHigh { get; set; }

public int dividendDate { get; set; }

public int earningsTimestamp { get; set; }

public int earningsTimestampStart { get; set; }

public int earningsTimestampEnd { get; set; }

public float trailingAnnualDividendRate { get; set; }

public float trailingPE { get; set; }

public float trailingAnnualDividendYield { get; set; }

public float epsTrailingTwelveMonths { get; set; }

public float epsForward { get; set; }

public float epsCurrentYear { get; set; }

public float priceEpsCurrentYear { get; set; }

public long sharesOutstanding { get; set; }

public float bookValue { get; set; }

public float fiftyDayAverage { get; set; }

public float fiftyDayAverageChange { get; set; }

public float fiftyDayAverageChangePercent { get; set; }

public float twoHundredDayAverage { get; set; }

public float twoHundredDayAverageChange { get; set; }

public float twoHundredDayAverageChangePercent { get; set; }

public long marketCap { get; set; }

public float forwardPE { get; set; }

public float priceToBook { get; set; }

public int sourceInterval { get; set; }

public int exchangeDataDelayedBy { get; set; }

public string averageAnalystRating { get; set; }

public bool tradeable { get; set; }

public string exchange { get; set; }

public string longName { get; set; }

public string messageBoardId { get; set; }

public string exchangeTimezoneName { get; set; }

public string exchangeTimezoneShortName { get; set; }

public int gmtOffSetMilliseconds { get; set; }

public string market { get; set; }

public bool esgPopulated { get; set; }

public string shortName { get; set; }

public string marketState { get; set; }

public string displayName { get; set; }

public string symbol { get; set; }

}