px.timeline Incorrectly interprets x_end datetimes

The px.timeline function incorrectly generates the end times of the bar traces. The end times are placed before the start times.

Python version 3.8.6
Plotly version 5.4

Steps to reproduce:

import datetime
import plotly.express as px
t0 = datetime.datetime.now()
tf = t0 + datetime.timedelta(hours=1)
px.timeline(x_start=[t0], x_end=[tf])

print(t0)
print(tf)

Produces

2021-11-16 12:21:14.800827  # t0
2021-11-16 13:21:14.800827  # tf

The resulting figure is below. Notice that the right edge of the bar is the same as the start time, but the left edge of the bar is something else entirely.

The behavior is the same when passing a dataframe and column names. If you generate a scatter plot using the same datetime objects, the output works as expected (shown below).

從 px.timeline 入口點開始，使用報告中顯示的 datetime 值重現問題，並將其 bar trace 的座標與使用相同值的散點圖進行比較。追蹤 x_start 和 x_end 如何轉換到 figure 中，然後驗證產生的 bar 是否具有預期的開始和結束時間，以及 dataframe-and-column-names 情況是否也能正確運作。