Python-pptx formatting datalabels after adding text

Question

As I needed to add custom text to a chart data labels in python-pptx I used

for point in plot.series[1].points:
   frame = point.data_label.text_frame
   frame.text = "Test "
   for run in frame.paragraphs[0].runs:
      run.font.size = Pt(10)
      run.font.color.rgb = RGBColor(0x0A, 0x42, 0x80)

This allowed me to change the font to the labels but I would need to rotate them. I saw the solution from This other thread but it does not work. Any ideas?

Answer 1

I believe you need to change the txPr (as in the thread you mention) but on the respective element child:

for all_series in range(0, len(plot.series)):
   for i in range(0, len(plot.series[all_series]._element)):
      if re.sub("{.*}", '', plot.series[all_series]._element[i].tag) == >"dLbls":
           txPr = plot.series[all_series]._element[i].get_or_add_txPr()
           txPr.bodyPr.set('rot', '-5400000')

So you need to access the "dLbls" child within the correct element index, the "[i]" is the difference to the mentioned thread. I use regular expressions to derive the name from the ".tag"-method. There is probably a better way to find the correct index, but this is at least one ;)

This solution iterates over all series, if you do not need this you can skip the first loop (assuming you want only the 1-series):

for i in range(0, len(plot.series[1]._element)):
    if re.sub("{.*}", '', plot.series[1]._element[i].tag) == "dLbls":
        txPr = plot.series[1]._element[i].get_or_add_txPr()
        txPr.bodyPr.set('rot', '-5400000')

Note, that this only applies to data labels which were set on the single point, so e.g. through

plot.series[1].points[0].data_label.text_frame.text = "Foo"

Hopefully this helps :)

Answer 2

You can try this custom function, feed in your plot variable, and other style properties as you needed. If we go at point level for data label then this wont work as we think, and below can help to achieve.

def apply_data_labels(plot,font,fontsize,numformat,rotate = False):
plot.has_data_labels = True
data_labels = plot.data_labels
data_labels.font.size = Pt(fontsize)
data_labels.font.name = font
if rotate == True:
    data_labels._element.get_or_add_txPr().bodyPr.set('rot','-5400000')
data_labels.number_format = numformat

and call this function with your plot variable for example.

apply_data_labels(chart.plots[0],'Invention',10,'#,##0;[Red]#,##0',rotate = True)