将图例线自定义为正方形

Question

我想将图例符号从线更改为正方形。示例代码如下：

import pandas as pd
import plotly.express as px
import plotly.graph_objects as go

def save_fig(fig,pngname):
    fig.write_image(pngname,format="png",width=600,height=400, scale=1)
    print("[[%s]]"%pngname)
    return

df = px.data.stocks()
print(df.columns)
df = df[['date','AMZN', 'AAPL']]

fig = go.Figure()
for name in df.columns:
    if name == 'date': continue
    trace = go.Scatter(
        x = df['date'],
        y = df[name],
        name=name,
    )
    fig.add_trace(trace)
        
save_fig(fig,"./demo.png")

正确的做法是什么？

Answer 1

建立在 @PenguinBlues' answer :

fig = go.Figure()

for name, color in zip(
    df.columns.difference(["date"]),
    fig.layout.template.layout.colorway
):
    trace = go.Scatter(
        x = df["date"],
        y = df[name],
        name=name,
        legendgroup=name,
        marker=dict(color=color),
        showlegend = False,
    )
    
    fig.add_trace(trace)   

    fig.add_shape(
        name=name,
        legendgroup=name,
        showlegend=True,
        type="rect",
        line=dict(width=0),
        fillcolor=color,
        y0=0, y1=0,
    )
    
fig.update_xaxes(range=[df["date"].min(), df["date"].max()])
fig.update_yaxes(range=[df.describe().loc["min"].min(),
                        df.describe().loc["max"].max()])
        

fig.show();

输出：