“期望一个数组.提供了类型“对象".如何解决我的Dash应用程序的DataTable函数中的此错误? [英] "Expected an array. Was supplied type `object`." How to solve this error in my DataTable function for my Dash app?

问题描述

请查看我的代码并滚动到我的 statsTable(symbols)函数，这就是我的错误出现的地方.

please look at my code and scroll to my statsTable(symbols) function, that is where my error comes up.

import dash
import dash_table as dt
import dash_bootstrap_components as dbc
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output
import plotly.express as px
import plotly.graph_objs as go
from dash.exceptions import PreventUpdate

import pandas as pd

from connect import *
from dash_tables import *


stock_ids = execute_query(conn, "SELECT DISTINCT id FROM security_price;")
stock_ids = [i[0] for i in stock_ids]
options = [{'label': i, 'value': i} for i in stock_ids]

app = dash.Dash(__name__, external_stylesheets=[dbc.themes.LUX],  meta_tags=[
        {"name": "viewport", "content": "width=device-width, initial-scale=1"}])
body = html.Div(
    [dbc.Jumbotron(
    [
        dbc.Container(
    [
        html.H1("SP500", className="display-4"),
        html.P(
            "Compare equities in the SP500 "
            "before you buy.",
            className="lead",
        ),
        html.P(
            "Enter the symbols that interest you "
            "and view how they compare",
            
        ),
        
    ], 
        fluid=True,
        )

    ], 
    fluid=True,
)
    , dbc.Row(dbc.Container(dcc.Dropdown(id="dynamic-dropdown", options=options, multi=True, placeholder="Select a Symbol", style={'margin-left': '20px', 'margin-right':'45px'}),fluid=True))

    , dbc.Row(dbc.Col(html.Div(children = [dcc.Graph(id='output-graph', config={'displayModeBar': False}, animate=True)], style={'padding': 10})))

        
    
    , dbc.Row([
           (html.Div(dbc.Container(dt.DataTable(id='table_stats', style_table={'margin-left': '20px', 'margin-right':'45px'}))))], justify="center")

            # lg=9, md=6, xs=4, style={'margin-left': '5px','padding': 10})
             #dbc.Col(html.Div(dbc.Alert("One of three columns", color="primary")), lg=3, md=4, xs=12, style={'padding' : 10})
            # # , dbc.Col(html.Div(dbc.Alert("One of three columns", color="primary")), lg=3, md=4, xs=12,style={'margin-right': '5px','padding': 10})
            # ], justify="center")

    , dbc.Row(dbc.Col(html.Div(dbc.Alert("This is one column", color="primary", style={'margin-top' : '25px' ,'margin-bot' : '25px'}))),style={'margin-left' : '25px' ,'margin-right' : '25px'}, justify="center")
        ])






app.layout = html.Div([body])




@app.callback(
dash.dependencies.Output('table_stats', 'data'),
[dash.dependencies.Input('dynamic-dropdown', 'value')])



def statsTable(symbols):
    print(symbols)
    if symbols == None:
        raise PreventUpdate
    
    placeholders = ", ".join(['%s' for _ in symbols])

    # PREPARED STATEMENT WITH PARAM PLACEHOLDERS
    sql = f"""SELECT id, companyname, marketcap
                     , to_char(100.0*week52change,'999D99%%'), week52high, week52low
                     , to_char(dividend_yield * 100, '99D99%%'), next_earnings_date
                     , pe_ratio, ROUND(beta,2) 
              FROM security_stats 
              WHERE security_stats.id IN ({placeholders})
           """

    print(sql)

    df = postgresql_to_dataframe_v1(conn, sql, symbols, stats_col)
    columns = df.columns
    data = df.to_dict('rows')

    
    table = dt.DataTable(data=data, columns=columns)
    print(table)

    return table




if __name__ == "__main__":
    app.run_server(debug = True)

这是 print(table)，为您提供我正在传递的内容的示例:

This is print(table) to give you an example of what I'm passing:

DataTable(columns=Index(['Symbol', 'Company', 'Market Cap', '1yr-Change', '52-Week High',
       '52-Week Low', 'Dividend Yield', 'Next Earnings Report', 'PE-Ratio',
       'Beta'],
      dtype='object'), data=[{'Symbol': 'RSG', 'Company': 'Republic Services  Inc.', 'Market Cap': 31604176866, '1yr-Change': '  13.21%', '52-Week High': Decimal('102.58'), '52-Week Low': Decimal('65.78'), 'Dividend Yield': '  1.70%', 'Next Earnings Report': datetime.date(2020, 10, 25), 'PE-Ratio': Decimal('29.9'), 'Beta': Decimal('0.87')}])

这是 print(data)，为您提供我正在传递的内容的示例:

This is print(data) to give you an example of what I'm passing:

[{'Symbol': 'RSG', 'Company': 'Republic Services  Inc.', 'Market Cap': 31604176866, '1yr-Change': '  13.21%', '52-Week High': Decimal('102.58'), '52-Week Low': Decimal('65.78'), 'Dividend Yield': '  1.70%', 'Next Earnings Report': datetime.date(2020, 10, 25), 'PE-Ratio': Decimal('29.9'), 'Beta': Decimal('0.87')}]

以下是Dash控制台中显示的错误:

Below is the error that appears in the Dash Console:

Invalid argument `data` passed into DataTable with ID "table_stats".
Expected an array.
Was supplied type `object`.

如何解决此错误?

推荐答案

您的回调具有以下输出:

Your callback has this output:

dash.dependencies.Output('table_stats'，'data')，

因此，您正在将返回的值提供给表的 data 属性.但这不是您的函数返回的结果.它返回一个数据表组件.

so you are supplying the returned value to the data prop of your table. But that's not what your function returns. It returns a datatable component.

您可能希望将输出更改为:

You probably will want to change your output to:

@app.callback(
[
    dash.dependencies.Output('table_stats', 'data'),
    dash.dependencies.Output('table_stats', 'columns'),
],
[dash.dependencies.Input('dynamic-dropdown', 'value')])

然后执行:

返回数据，列

在您的回调中.

这篇关于“期望一个数组.提供了类型“对象".如何解决我的Dash应用程序的DataTable函数中的此错误?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！