topic Re: Python Visual in Power BI: set_facecolor() not working after DataFrame transpose in Developer

Python Visual in Power BI: set_facecolor() not working after DataFrame transpose

shabnam12 — Tue, 22 Apr 2025 12:35:31 GMT

Hi Power BI Community,

I’m using Python visuals in Power BI and rendering a stylized table using matplotlib.pyplot.table(). The setup works perfectly when using a regular DataFrame — I'm able to change cell background color using cell.set_facecolor(), and also apply font customizations like set_text_props() for bold text or font color.

However, as soon as I transpose the DataFrame (using .T) — which I do to make months as columns and metrics as rows — the set_facecolor() styling silently fails.

Here's a breakdown:

✅ set_facecolor() works before transpose
❌ set_facecolor() stops working after transpose
✅ set_text_props() continues working fine even after transpose
✅ No error is thrown; just the background color isn't rendered in the visual
✅ Using matplotlib.use('Agg') and the rest of the visual renders correctly

I’ve confirmed this behavior by building up the script step-by-step. As soon as .T is applied on the DataFrame, the table still renders and fonts update, but background color is completely ignored.

table = ax.table( cellText=df_transposed.values.tolist(), rowLabels=df_transposed.index.tolist(), colLabels=df_transposed.columns.tolist(), loc='upper left' ) for (row, col), cell in table.get_celld().items(): if row == 0: cell.set_facecolor('#ffeecc') # Not working cell.set_text_props(weight='bold', color='black') # Works fine

💭 My Question:

Is this a known rendering limitation for matplotlib inside Power BI Python visuals when using transposed data?
Are there any known workarounds to make set_facecolor() work after .T?
Or is the only option to avoid transposing and restructure the table layout manually?

Any insights or suggestions would be really helpful.

Thanks in advance!

Re: Python Visual in Power BI: set_facecolor() not working after DataFrame transpose

v-echaithra — Thu, 08 May 2025 13:37:59 GMT

Hi shabnam12 ,

Your visual table’s layout looks correct, but the internal table grid may not treat the new header row in the same way. Fonts work because text props apply to any cell, but colors fail.

Try targeting cells by column labels rather than row numbers, manually add a header row as part of celltext

Regards,
Chaithra.

Re: Python Visual in Power BI: set_facecolor() not working after DataFrame transpose

v-echaithra — Mon, 12 May 2025 06:16:44 GMT

Hi shabnam12 ,

We wanted to kindly follow up to check if the solution provided for the issue worked? or Let us know if you need any further assistance?
If our response addressed, please mark it as Accept as solution and click Yes if you found it helpful.

Regards,
Chaithra.

Re: Python Visual in Power BI: set_facecolor() not working after DataFrame transpose

v-echaithra — Thu, 15 May 2025 05:34:53 GMT

Hi shabnam12 ,

As we haven’t heard back from you, we wanted to kindly follow up to check if the solution provided for the issue worked? or Let us know if you need any further assistance?
If our response addressed, please mark it as Accept as solution and click Yes if you found it helpful.

Regards,
Chaithra.

Re: Python Visual in Power BI: set_facecolor() not working after DataFrame transpose

v-echaithra — Thu, 22 May 2025 05:46:49 GMT

Hi shabnam12 ,

Regards,
Chaithra.