Try something like this (building on previous question). You should really invest time in designing your code before you ask questions like this:
import win32com.client
import sys # <- obsolete not used
import os
import glob # style guide one import per line
Application = win32com.client.Dispatch("PowerPoint.Application")
Application.Visible = True
ppt_files = glob.glob('*.ppt')
for file in ppt_files:
file = os.path.abspath(file)
Presentation = Application.Presentations.Open(file)
for Slide in Presentation.Slides:
for Shape in Slide.Shapes:
try:
Shape.TextFrame.TextRange.Font.Name = "Arial"
Shape.TextFrame.TextRange.Font.Size = "12"
Shape.TextFrame.TextRange.Font.Color.RGB = "000000"
except:
pass
Presentation.Save()
Presentation.Close()
Application.Quit()