Python如何制作数据看板？Dash框架入门

import dash
from dash import html, dcc
import plotly.express as px
import pandas as pd

# 1. 初始化Dash应用
app = dash.Dash(__name__)

# 准备一些简单的数据
df = pd.DataFrame({
    "水果": ["苹果", "橙子", "香蕉", "苹果", "橙子", "香蕉"],
    "数量": [4, 1, 2, 2, 4, 5],
    "城市": ["北京", "北京", "北京", "上海", "上海", "上海"]
})

# 创建一个简单的柱状图
fig = px.bar(df, x="水果", y="数量", color="城市", barmode="group")

# 2. 定义应用布局
app.layout = html.Div(children=[
    html.H1(children='我的第一个Dash数据看板'),

    html.Div(children='''
        一个简单的水果销售数据展示。
    '''),

    dcc.Graph(
        id='example-graph',
        figure=fig
    )
])

# 3. 运行应用
if __name__ == '__main__':
    app.run_server(debug=True)

dash.Dash(__name__)

dash.dependencies

# ... (前面的导入和df定义不变) ...

app.layout = html.Div([
    html.H1("城市水果销售看板"),
    dcc.Dropdown(
        id='city-selector',
        options=[{'label': i, 'value': i} for i in df['城市'].unique()],
        value='北京', # 默认选中北京
        clearable=False
    ),
    dcc.Graph(id='live-update-graph')
])

@app.callback(
    dash.Output('live-update-graph', 'figure'),
    dash.Input('city-selector', 'value')
)
def update_graph(selected_city):
    filtered_df = df[df['城市'] == selected_city]
    fig = px.bar(filtered_df, x="水果", y="数量", title=f"{selected_city}水果销售情况")
    return fig

# ... (运行app的代码不变) ...

# ... (导入和df定义不变) ...

app.layout = html.Div([
    html.H1("动态水果销售分析"),
    html.Div([
        html.Label("选择城市:"),
        dcc.Dropdown(
            id='city-dropdown',
            options=[{'label': i, 'value': i} for i in df['城市'].unique()],
            value='北京',
            clearable=False,
            style={'width': '50%', 'display': 'inline-block'}
        ),
        html.Label("选择数量范围:", style={'marginLeft': '20px'}),
        dcc.RangeSlider(
            id='quantity-slider',
            min=df['数量'].min(),
            max=df['数量'].max(),
            step=1,
            value=[df['数量'].min(), df['数量'].max()],
            marks={str(i): str(i) for i in range(df['数量'].min(), df['数量'].max() + 1)},
            tooltip={"placement": "bottom", "always_visible": True},
            style={'width': '40%', 'display': 'inline-block', 'marginLeft': '10px'}
        )
    ]),
    dcc.Graph(id='filtered-sales-graph')
])

@app.callback(
    dash.Output('filtered-sales-graph', 'figure'),
    [dash.Input('city-dropdown', 'value'),
     dash.Input('quantity-slider', 'value')]
)
def update_filtered_graph(selected_city, quantity_range):
    low_qty, high_qty = quantity_range
    filtered_df = df[
        (df['城市'] == selected_city) &
        (df['数量'] >= low_qty) &
        (df['数量'] <= high_qty)
    ]
    fig = px.bar(filtered_df, x="水果", y="数量",
                 title=f"{selected_city} - 数量在 {low_qty}-{high_qty} 的水果销售")
    return fig

# ... (运行app的代码不变) ...

update_filtered_graph

city-dropdown

quantity-slider

app.layout = html.Div([
    html.Div([ # 左侧区域
        html.H2("控制面板"),
        dcc.Dropdown(...),
        dcc.RangeSlider(...)
    ], style={'width': '30%', 'float': 'left', 'padding': '20px'}),

    html.Div([ # 右侧图表区域
        html.H2("数据可视化"),
        dcc.Graph(...)
    ], style={'width': '65%', 'float': 'right', 'padding': '20px'})
])

style

assets

# assets/styles.css
body {
    font-family: Arial, sans-serif;
    margin: 0;
    background-color: #f4f4f4;
}
.container {
    max-width: 1200px;
    margin: 20px auto;
    background-color: white;
    padding: 20px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
.row {
    display: flex;
    flex-wrap: wrap;
}
.col-6 {
    flex: 0 0 50%;
    padding: 10px;
    box-sizing: border-box;
}

className

app.layout = html.Div(className='container', children=[
    html.Div(className='row', children=[
        html.Div(className='col-6', children=[
            html.H2("控制面板"),
            dcc.Dropdown(...)
        ]),
        html.Div(className='col-6', children=[
            html.H2("数据可视化"),
            dcc.Graph(...)
        ])
    ])
])

import dash_bootstrap_components as dbc

app = dash.Dash(__name__, external_stylesheets=[dbc.themes.BOOTSTRAP])

app.layout = dbc.Container([
    dbc.Row([
        dbc.Col(html.H1("我的Dash看板"), width=12, className="text-center my-4")
    ]),
    dbc.Row([
        dbc.Col([
            dbc.Card([
                dbc.CardHeader("数据筛选"),
                dbc.CardBody([
                    html.P("选择城市:"),
                    dcc.Dropdown(
                        id='city-dropdown-dbc',
                        options=[{'label': i, 'value': i} for i in df['城市'].unique()],
                        value='北京',
                        clearable=False
                    )
                ])
            ])
        ], width=4),
        dbc.Col([
            dbc.Card([
                dbc.CardHeader("图表展示"),
                dbc.CardBody([
                    dcc.Graph(id='filtered-sales-graph-dbc')
                ])
            ])
        ], width=8)
    ])
], fluid=True) # fluid=True让容器宽度充满整个屏幕

dbc.themes.BOOTSTRAP

dbc.Container

dbc.Row

dbc.Col

dbc.Card