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

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!