How to control the font size of title in pptx generated using python-pptx?

Question

I have created a simple python app that converts each line of a text file into the title of each slide in a pptx file, using the python-pptx module and Bing AI. The app works fine, except for one issue: the font size of the title is too large and I cannot change it through the code.

I have tried different ways to adjust the font size, such as using the font.size attribute of the text_frame.paragraphs[0].font object, as suggested in this answer, but none of them worked. I have also read the python-pptx documentation but I could not find a solution. I kept getting similar problem like this.

line 31, in create_presentation title_shape.font.size = Pt(32) ^^^^^^^^^^^^^^^^ AttributeError: 'SlidePlaceholder' object has no attribute 'font'

How can I change the font size of the slide title in python-pptx? Any help would be appreciated. Thank you.

import tkinter as tk
from tkinter import filedialog
from pptx import Presentation
from pptx.util import Pt
import os # Import the os module

def create_presentation():
    # Open a file dialog to select a text file
    root = tk.Tk()
    root.withdraw()
    file_path = filedialog.askopenfilename()
    
    # Read the text file and get the slide titles
    with open(file_path) as f:
        slide_titles = f.read().splitlines()
    
    # Create a new PowerPoint presentation
    prs = Presentation()

    # Use the title and content slide layout (index 1)
    title_and_content_layout = prs.slide_layouts[1]

    # Add a slide for each title in the list
    for title in slide_titles:
        # Remove the leading hyphen or dash from the title
        title = title.lstrip('- ')
        slide = prs.slides.add_slide(title_and_content_layout)
        title_shape = slide.shapes.title
        title_shape.text = title
        title_shape.font.size = Pt(32)

        # Change the font size in title to 32 pt

        # You can add some content text here, or leave it blank
        # content_shape = slide.placeholders[1]
        # content_shape.text = "say something here"


    # Get the directory of the input file
    dir_path = os.path.dirname(file_path)

    # Extract the filename from the file path
    file_name = os.path.basename(file_path)

    # Split the file name into base and extension
    base, ext = os.path.splitext(file_name)

    # Replace the extension with .pptx
    new_file_name = base + ".pptx"

    # Join the directory and the new file name
    output_path = os.path.join(dir_path, new_file_name)

    # Save the PowerPoint presentation
    prs.save(output_path)
    root.destroy()

create_presentation()

Answer 1

A textframe contains run objects. Apply the font.size change to that.