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，我无法共享程序输出的实际图像，但它看起来与上图中的完全相同。据我测试，这应该与任何明确的数字。
我希望这对一些人有用。大家好！