如何使用 Plotly Express 创建子图

Question

如果您像我一样，您喜欢 Plotly Express，但是当您遇到 Express 返回的数字无法使用“make_subplots()”的问题时，您会感到沮丧，因为 make_subplots 需要跟踪而不是数字。 在这篇文章中，我想分享我自己的解决方案，了解如何仅使用 Plotly Express（和 plotly.subplots）创建包含两种不同类型图形（如下所示）的子图

Answer 1

解决方案：

import plotly.express as px
import plotly.subplots as sp

# Create figures in Express
figure1 = px.line(my_df)
figure2 = px.bar(my_df)

# For as many traces that exist per Express figure, get the traces from each plot and store them in an array.
# This is essentially breaking down the Express fig into it's traces
figure1_traces = []
figure2_traces = []
for trace in range(len(figure1["data"])):
    figure1_traces.append(figure1["data"][trace])
for trace in range(len(figure2["data"])):
    figure2_traces.append(figure2["data"][trace])

#Create a 1x2 subplot
this_figure = sp.make_subplots(rows=1, cols=2) 

# Get the Express fig broken down as traces and add the traces to the proper plot within in the subplot
for traces in figure1_traces:
    this_figure.append_trace(traces, row=1, col=1)
for traces in figure2_traces:
    this_figure.append_trace(traces, row=1, col=2)

#the subplot as shown in the above image
final_graph = dcc.Graph(figure=this_figure)

由于我正在处理的项目数据的敏感性，我无法分享我的程序 output 的实际图像，但它看起来与上图中的完全一样。 据我测试，这应该适用于任何 Express 人物。

我希望这对某些人有用。 祝大家策划愉快！

Answer 2

公认的答案很好，我想提一下针对它的第一条评论的一个小修改，这只是为了显示一些特定子图的传说。 当所有子图共享相同的图例时，我发现此修改非常有用，并且让单个图例重复多次似乎是多余的。

这是诀窍。 图形的每个轨迹都有自己的'showlegend'属性（Plotly Express 图形的默认设置为 True），因此您可以通过迭代将其设置为 False，就像我对图 2 所做的那样。

# I largely keep the codes and comments the same as the original answer, with the modification highlighted under '#######'
my_df = px.data.medals_long()

# Create figures in Express
figure1 = px.bar(my_df, x = "nation", y = "count", color = "medal")
figure2 = px.line(my_df, x = "nation", y = "count", color = "medal")

# For as many traces that exist per Express figure, get the traces from each plot and store them in an array.
# This is essentially breaking down the Express fig into its traces
figure1_traces = []
figure2_traces = []
for trace in range(len(figure1["data"])):
    figure1_traces.append(figure1["data"][trace])
for trace in range(len(figure2["data"])):
    ############ The major modification. Manually set 'showlegend' attribute to False. ############
    figure2["data"][trace]['showlegend'] = False             
    figure2_traces.append(figure2["data"][trace])
    
# Create a 1x2 subplot
this_figure = make_subplots(rows = 1, cols = 2, subplot_titles = ['Bar', 'Line'])
this_figure.update_layout(height = 500, width = 1200, title_text = "Medals count by country", title_font_size = 25)

# Get the Express fig broken down as traces and add the traces to the proper plot within the subplot
for traces in figure1_traces:
    this_figure.append_trace(traces, row = 1, col = 1)
for traces in figure2_traces:
    this_figure.append_trace(traces, row = 1, col = 2)
    
this_figure.show()

如果不进行此修改，每个组的图例将显示两次，但它们仍然只能同时显示/隐藏。