Bar chart with `facet_row` only rendering data for one facet

I have a bar chart with a facet_row defined as follows, with example data.

Example code and data for `facet_row` bug

tmp_data = [
    {
        "date": "2022-04-17",
        "role_name": "Nurse",
        "work_type": "Cleaning",
        "daily_total_minutes": 45,
        "percent_of_daily_role_total_minutes": 0.41,  
    },
    {
        "date": "2022-04-17",
        "role_name": "Nurse",
        "work_type": "Food preparation",
        "percent_of_daily_role_total_minutes": 0.59,  
    },
    {
        "date": "2022-04-17",
        "role_name": "Volunteer",
        "work_type": "Cleaning",
        "percent_of_daily_role_total_minutes": 0.26,  
    },
    {
        "date": "2022-04-17",
        "role_name": "Volunteer",
        "work_type": "Food preparation",
        "percent_of_daily_role_total_minutes": 0.74,  
    },
    {
        "date": "2022-05-06",
        "role_name": "Volunteer",
        "work_type": "Food preparation",
        "percent_of_daily_role_total_minutes": 1.0,  
    },
    {
        "date": "2022-05-07",
        "role_name": "Volunteer",
        "work_type": "Cleaning",
        "percent_of_daily_role_total_minutes": 0.49,  
    },
    {
        "date": "2022-05-07",
        "role_name": "Volunteer",
        "work_type": "Food preparation",
        "percent_of_daily_role_total_minutes": 0.51,  
    },
]

daily_work_by_caregiver_role_and_type_with_percent_chart = px.bar(
    tmp_data,
    x="date",
    y="percent_of_daily_role_total_minutes",
    facet_row="role_name",
    color="work_type",
    title=_("Daily work percent by caregiver role and work type"),
    labels={
        "role_name": _("Caregiver role"),
        "percent_of_daily_role_total_minutes": _("Work percent"),
        "work_type": _("Type of work"),
    },
    text_auto=True,
)
daily_work_by_caregiver_role_and_type_with_percent_chart.layout.yaxis.tickformat = ",.0%"

# render the chart
daily_work_by_caregiver_role_and_type_with_percent_chart.to_html()

When rendering the chart, the x axis correctly determines the data are dates and the y-axis on the bottom facet is correctly formatted as a percentage with the data rendering. However, the top facet doesn’t render any data.

I have tried both with and without specifying the yaxis.tickformat and get a similar result, where the first facet series doesn’t render any data.

[nicolaskruchten]

So what’s happening here is that the upper facet has only one day’s worth of data in it, and the automatic calculation of the bar width results in a single extremely thin bar being shown around midnight of April 17 (the bar is less than a millisecond wide). This is pretty counter-intuitive but that’s what’s happening. You can force the bars to be one day wide by calling .update_traces(width=24*60*60*1000) on the figure.

@alexcjohnson I can see this being more or less reasonable behaviour for a single subplot, but for matched axes, I could also see the bar width being computed while taking into account all bars on the whole set of axes, no?

[nicolaskruchten]

Great, happy I was able to help, sorry for the friction you’ve been encountering 😃