问题

以下是您要翻译的内容：

我在将从API提供的数据反序列化后的JSON转换为Polars DataFrame方面遇到了困难。

以下是我的结构和定义的函数：

// 用于期权价格查询的结构
#[derive(Serialize, Deserialize, Debug)]
pub struct OptionResponse {
    pub tables: Vec<OptionTable>,
}

#[derive(Serialize, Deserialize, Debug)]
pub struct OptionTable {
    pub table: OptionDataTable,
}

#[derive(Serialize, Deserialize, Debug)]
pub struct OptionDataTable {
    pub volume: Vec<f64>,
    pub open: Vec<f64>,
    pub close: Vec<f64>,
    pub high: Vec<f64>,
    pub low: Vec<f64>,
}

pub async fn ifind_option_read(option_code: &str, access_token: &str, start_time_str: &str, end_time_str: &str) -> Result<(), Box<dyn std::error::Error>> {
    let url = "https://quantapi.51ifind.com/api/v1/high_frequency";

    // 创建高频价格请求
    let request_data = maplit::hashmap! {
        "codes" => option_code,
        "indicators" => "volume,open,close,high,low",
        "starttime" => start_time_str,
        "endtime" => end_time_str,
    };
    let request_json = serde_json::to_string(&request_data)?;

    // 发送HTTP POST请求
    let client = reqwest::Client::new();
    let response = client
        .post(url)
        .header(reqwest::header::CONTENT_TYPE, "application/json")
        .header("access_token", access_token)
        .body(request_json)
        .send()
        .await?;
    let response_json: OptionResponse = response.json().await?;
    let response_body = &response_json.tables[0].table;
    println!("{:?}", &response_body);
    // 将response_json转换为字节数组
    let json_bytes = serde_json::to_vec(&response_body)?;
    // 通过JsonReader的方法将响应读入df
    let df = JsonReader::new(Cursor::new(json_bytes))
        .with_batch_size(1024)
        .infer_schema_len(None)
        .finish().unwrap();
    println!("{:?}", df);
    Ok(())
}

返回的response_body看起来对我来说非常正常，类似于：

OptionDataTable { volume: [0.0, 0.0, 0.0], open: [1263.0, 1263.0, 1263.0], close: [1263.0, 1263.0, 1263.0], high: [1263.0, 1263.0, 1263.0], low: [1263.0, 1263.0, 1263.0] }

尽管如此，JsonReader无法将其读取为DataFrame。这让我感到困惑。这是JSON格式的问题吗？

<details>
<summary>英文:</summary>
i am struggling with conversion from JSON(deserialised from API-provicded data) to polars dataframe.
below are my structs and defined function:
```rust
//  structs for option price query
#[derive(Serialize, Deserialize, Debug)]
pub struct OptionResponse {
pub tables: Vec&lt;OptionTable&gt;,
}
#[derive(Serialize, Deserialize, Debug)]
pub struct OptionTable {
pub table: OptionDataTable,
}
#[derive(Serialize, Deserialize, Debug)]
pub struct OptionDataTable {
pub volume: Vec&lt;f64&gt;,
pub open: Vec&lt;f64&gt;,
pub close: Vec&lt;f64&gt;,
pub high: Vec&lt;f64&gt;,
pub low: Vec&lt;f64&gt;,
}
pub async fn ifind_option_read(option_code: &amp;str, access_token: &amp;str, start_time_str: &amp;str, end_time_str: &amp;str) -&gt; Result&lt;(), Box&lt;dyn std::error::Error&gt;&gt; {
let url = &quot;https://quantapi.51ifind.com/api/v1/high_frequency&quot;;
// create the high-frequency prices request
let request_data = maplit::hashmap! {
&quot;codes&quot; =&gt; option_code,
&quot;indicators&quot; =&gt; &quot;volume,open,close,high,low&quot;,
&quot;starttime&quot; =&gt; start_time_str,
&quot;endtime&quot; =&gt; end_time_str,
};
let request_json = serde_json::to_string(&amp;request_data)?;
// send the HTTP POST request
let client = reqwest::Client::new();
let response = client
.post(url)
.header(reqwest::header::CONTENT_TYPE, &quot;application/json&quot;)
.header(&quot;access_token&quot;, access_token)
.body(request_json)
.send()
.await?;
let response_json: OptionResponse = response.json().await?;
let response_body = &amp;response_json.tables[0].table;
println!(&quot;{:?}&quot;, &amp;response_body);
// Convert response_json to byte array
let json_bytes = serde_json::to_vec(&amp;response_body)?;
// read the response into df, per method of JsonReader
let df = JsonReader::new(Cursor::new(json_bytes))
.with_batch_size(1024)
.infer_schema_len(None)
.finish().unwrap();
println!(&quot;{:?}&quot;, df);
Ok(())
}

the response_body returned looks very normal to me and looks like

OptionDataTable { volume: [0.0, 0.0, 0.0], open: [1263.0, 1263.0, 1263.0], close: [1263.0, 1263.0, 1263.0], high: [1263.0, 1263.0, 1263.0], low: [1263.0, 1263.0, 1263.0] }

neverthless the JsonReader cant read it as a df.
this is confusing. is this a json format problem?

答案1

得分: 0

以前在polars/polars-json/src/json/deserialize.rs中的deserialize函数使用了todo!宏，导致了这个错误。

pub fn deserialize(json: &BorrowedValue, data_type: DataType) -> Result<Box<dyn Array>, Error> {
    match json {
        BorrowedValue::Array(rows) => match data_type {
            DataType::LargeList(inner) => Ok(_deserialize(rows, inner.data_type)),
            _ => todo!("从非数组数据类型中读取数组"),
        },
        _ => todo!("从非数组JSON中读取数组"),
    }
}

现在用Ok(_deserialize(&[json], data_type))替代了。

通过提交#207e0b9，现在一切都应该正常了。

pub fn deserialize(json: &BorrowedValue, data_type: DataType) -> Result<Box<dyn Array>, Error> {
    match json {
        BorrowedValue::Array(rows) => match data_type {
            DataType::LargeList(inner) => Ok(_deserialize(rows, inner.data_type)),
            _ => todo!("read an Array from a non-Array data type"),
        },
        _ => todo!("read an Array from a non-Array JSON"),
    }
}