Bug when using categorical axes and colors in plotly.express

[camold]

According to the documentation:

By default, Plotly Express lays out categorical data in the order in which it appears in the underlying data.

However, when using categorical axes in conjunction with colors, things do not show up in the order of the underlying data anymore.

import plotly.express as px
pdata_x = ["A","B",None,"B","C",None,"C","D", None, "D", "E", None]
pdata_y = [1,1,None,2,2,None,3,3,None,4,4,None]
pdata_color = [1,1,1,2,2,2,2,2,2,1,1,1]
px.line(x=pdata_x, y=pdata_y, color=pdata_color).show()

Output is

When not(!) using colors, we would get the correct output:

px.line(x=pdata_x, y=pdata_y ).show()

For anyone who comes across this problem, a temporary fix is explicitely specifying the category order:

px.line(x=pdata_x, y=pdata_y, color=pdata_color, category_orders={"x":["A","B","C","D"]}).show()

plotly==4.14.3
Python 3.8.0 (default, Feb 25 2021, 22:10:10)

[camold]

Reconfirmed on plotly 6.1.2 and python 3.13.4 on Windows 11. Any news on this one?

[gvwilson]

thanks @camold - unfortunately we don't have anyone to put on this right now, but we'd be happy to prioritize review of a community PR.