Python pptx (Power Point) Find and replace text (ctrl + H)

Question

Question in Short: How can I use the find and replace option (Ctrl+H) using the Python-pptx module?

Example Code:

from pptx import Presentation

nameOfFile = "NewPowerPoint.pptx" #Replace this with: path name on your computer + name of the new file.

def open_PowerPoint_Presentation(oldFileName, newFileName):
    prs = Presentation(oldFileName)

    prs.save(newFileName)
open_PowerPoint_Presentation('Template.pptx', nameOfFile)

I have a Power Point document named "Template.pptx". With my Python program I am adding some slides and putting some pictures in them. Once all the pictures are put into the document it saves it as another power point presentation.

The problem is that this "Template.pptx" has all the old week numbers in it, Like "Week 20". I want to make Python find and replace all these word combinations to "Week 25" (for example).

Answer 1

Posting code from my own project because none of the other answers quite managed to hit the mark with strings that have complex text with multiple paragraphs without losing formating:

prs = Presentation('blah.pptx')

# To get shapes in your slides
slides = [slide for slide in prs.slides]
shapes = []
for slide in slides:
    for shape in slide.shapes:
        shapes.append(shape)

def replace_text(self, replacements: dict, shapes: List):
    """Takes dict of {match: replacement, ... } and replaces all matches.
    Currently not implemented for charts or graphics.
    """
    for shape in shapes:
        for match, replacement in replacements.items():
            if shape.has_text_frame:
                if (shape.text.find(match)) != -1:
                    text_frame = shape.text_frame
                    for paragraph in text_frame.paragraphs:
                        for run in paragraph.runs:
                            cur_text = run.text
                            new_text = cur_text.replace(str(match), str(replacement))
                            run.text = new_text
            if shape.has_table:
                for row in shape.table.rows:
                    for cell in row.cells:
                        if match in cell.text:
                            new_text = cell.text.replace(match, replacement)
                            cell.text = new_text

replace_text({'string to replace': 'replacement text'}, shapes)