Python Dash 模块：深入探索

import dash  # 导入Dash模块
import dash_core_components as dcc  # 导入核心组件
import dash_html_components as html  # 导入HTML组件
from dash import Input, Output  # 导入输入输出功能
import plotly.express as px  # 导入Plotly表达式模块
import pandas as pd  # 导入Pandas模块

# 加载示例数据集
df = px.data.iris()  # 使用Plotly自带的iris数据集

# 初始化Dash应用
app = dash.Dash(__name__)

# 布局设计
app.layout = html.Div([
    dcc.Dropdown(
        id='dropdown',
        options=[{'label': i, 'value': i} for i in df['species'].unique()],  # 下拉菜单选项
        value='setosa'  # 默认选中值
    ),
    dcc.Graph(id='graph')  # 生成图表区域
])

# 回调函数定义
@app.callback(
    Output('graph', 'figure'),  # 输出图表
    Input('dropdown', 'value')  # 输入为下拉选项
)
def update_graph(selected_species):
    filtered_df = df[df['species'] == selected_species]  # 根据选中的物种筛选数据
    fig = px.scatter(filtered_df, x='sepal_width', y='sepal_length', color='species')  # 创建散点图
    return fig  # 输出图表

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

import dash
from dash import dcc, html
import plotly.graph_objs as go
import random

# 初始化Dash应用
app = dash.Dash(__name__)

# 布局设计
app.layout = html.Div([
    dcc.Graph(id='live-update-graph'),  # 实时更新图表
    dcc.Interval(
        id='interval-component',  # 时间间隔组件
        interval=1*1000,  # 每秒更新
        n_intervals=0  # 更新次数
    )
])

# 回调函数定义
@app.callback(
    dash.dependencies.Output('live-update-graph', 'figure'),
    [dash.dependencies.Input('interval-component', 'n_intervals')]
)
def update_graph(n):
    x = list(range(10))  # X轴坐标
    y = [random.randint(1, 10) for _ in range(10)]  # 随机生成Y轴坐标
    figure = go.Figure(data=[go.Scatter(x=x, y=y, mode='lines+markers')])  # 创建线图
    return figure  # 输出实时更新的图表

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

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

# 创建数据集
df = pd.DataFrame({
    "Fruit": ["Apples", "Oranges", "Bananas"],
    "Amount": [4, 1, 2],
    "City": ["SF", "SF", "LA"],
})

# 初始化Dash应用
app = dash.Dash(__name__)

# 布局设计
app.layout = html.Div([
    dash_table.DataTable(
        data=df.to_dict('records'),  # 将DataFrame转换为字典格式
        columns=[{"name": i, "id": i} for i in df.columns],  # 定义表头
    ),
    dcc.Graph(
        id='bar-chart',  # 条形图
        figure=px.bar(df, x='Fruit', y='Amount', color='City')  # 创建条形图
    )
])

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