如何显示带有我使用 Dash 上传组件上传的文件的 pandas 数据框？

Question

我正在按照本指南和文档将 excel 文件上传到仪表板：https://dash.plot.ly/dash-core-components/upload

我想知道如何在 pandas 数据框中显示我的上传结果。我的代码概述如下。从本质上讲，我的表格是某些百分比的状态细分，我正在尝试将其上传到我的仪表板中。

import base64
import datetime
import io

import dash
from dash.dependencies import Input, Output, State
import dash_core_components as dcc
import dash_html_components as html
import dash_table

import pandas as pd


external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)

app.layout = html.Div([
    dcc.Upload(
        id='upload-data',
        children=html.Div([
            'Drag and Drop or ',
            html.A('Select Files')
        ]),
        style={
            'width': '100%',
            'height': '120px',
            'lineHeight': '60px',
            'borderWidth': '1px',
            'borderStyle': 'dashed',
            'borderRadius': '5px',
            'textAlign': 'center',
            'margin': '10px'
        },
        # Allow multiple files to be uploaded
        multiple=True
    ),
    html.Div(id='output-data-upload'),
])


def parse_contents(contents, filename, date):
    content_type, content_string = contents.split(',')

    decoded = base64.b64decode(content_string)
    try:
        if 'csv' in filename:
            # Assume that the user uploaded a CSV file
            df = pd.read_csv(
                io.StringIO(decoded.decode('utf-8')))
        elif 'xls' in filename:
            # Assume that the user uploaded an excel file
            df = pd.read_excel(io.BytesIO(decoded))
    except Exception as e:
        print(e)
        return html.Div([
            'There was an error processing this file.'
        ])

def generate_table(df, max_rows=10):
    return html.Table(
        # Header
        [html.Tr([html.Th(col) for col in df.columns])] +

        # Body
        [html.Tr([
            html.Td(df.iloc[i][col]) for col in df.columns
        ]) for i in range(min(len(df), max_rows))]
    )

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)

app.layout = html.Div(children =[
    html.H4(children = 'test'),
    dcc.Dropdown( id = 'dropdown', options = [
        {'label' : i , 'value' : i} for i in df.state.unique()
    ],  multi = True, placeholder = 'Filter by State'),
    html.Div(id='table-container'),
        ])



def display_table(dropdown_value):

    if dropdown_value is None:
        return generate_table(df)


    #x = df[df['state'] == str(dropdown_value)]

    return html.Div([
        html.H5(filename),
        html.H6(datetime.datetime.fromtimestamp(date)),
        generate_table(df[df['state'].isin(dropdown_value)])

#app.css.append_css({"external_url": "https://codepen.io/chriddyp/pen/bWLwgP.css"})


@app.callback(
    dash.dependencies.Output('table-container', 'children'),
    [dash.dependencies.Input('dropdown','value')])


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

Answer 1

嗨@ntwong，我建议使用 dash_tables 来显示数据框，它是您将获得的最接近的数据框。这是一些使其工作的基本代码：

import dash_table
import pandas as pd
import dash_html_components as html

# create your dataframe "df" from your data idk what method you are using

    html.Div([
       dash_table.DataTable(data=df.to_dict("rows"), columns = [{"id": x, "name": x} for x in df.columns])
    ])

只需将代码放在脚本正文中即可。

Answer 2

不鼓励渲染原始 HTML，其他 here 已经描述了将解析的 html 转换为 dash-html-components 以与 dash_table 一起使用的函数。您可以通过为其提供正确的样式信息来使表格“看起来”像本机 jupyter 中的表格 - 或者您可以下载 dash-dangerously-set-inner-html 包，它可以让您显示它。

一个问题是，当您执行df.to_html() 时，pandas 只返回一个基本的 html，而不是像 question 那样带有任何样式属性 - 您可以通过渲染 df 然后获取 html 来解决（见下文）。然后解析 html，将样式提取到样式字典中。然后也许您可以使用 style_table/style_cell 属性将这些样式传递给 dash_table。

html = (df.style.render())

查看此guide 了解有关构建表的更多信息，