【Python×PowerPoint】Create Presentation File and Slides with python-pptx

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＜Concept of our website “More Freedom with Python”＞

This site aims to automate troublesome daily tasks and improve efficiency using Python, currently the most popular programming language. The goal is to introduce a variety of useful libraries (modules) in each issue.

Why?　Why Python…

What?　Automate…

When we think of the most familiar applications used in the business scene, the first ones that come to mind are probably MS-Office’s 「Excel」, 「Word」, and 「PowerPoint」.

Because they are “standard indispensable tools” that are used daily, the impact of automating and improving the efficiency of these related tasks can be extremely large.

Therefore, in this series of articles, we would like to introduce a method and library for operating the spreadsheet software PowerPoint, which is considered to be the most frequently used of all Office applications, using Python.

Excel has so many features that it is impossible to cover them all in this article alone. We will provide detailed explanations over a series of articles on the following topics

Now, in this first article of the series, I would like to explain “How to Introduce Libraries and Create Files and Slides”.

Please stay with us until the end of this article as you will be able to “do and understand” the following.

１. Overview of “python-pptx” library

The standard way to manipulate PowerPoint from Python is to use an external library called “python-pptx“. Using ”python-pptx”, you can do most of the file creation and editing tasks without launching PowerPoint.

Other languages that can control Office applications. VisualBasic (including VBA) in .Net, and a library called 「Pywin32」 that has been ported to Python. The “Office Developer Center’s” 「VBA Reference」is a good reference for these.

On the other hand, the specification of python-pptx is completely different from them.
The official document of python-pptx is the following URL.

python-pptx Official Documents (API Document)

https://openpyxl.readthedocs.io/en/stable/

1.1 Instal and Operation

Python-pptx is not bundled with ”Anacoda” and must be installed using “pip” or “setup.py”.

Install by entering the following command at the Anaconda prompt, etc.

pip install python-pptx

Note that manual installation by “setup.py” does not check for other packages (PIL and xlswWriter) that have dependencies, so we recommend installing with the “pip” command if possible.

python setup.py

Next, import some classes from the pptx module and check its operation.

Try entering and executing the following two lines in an interpreter, etc.

from pptx import  Presentation
prs = Presentation()

If no error messages are displayed at this point, the installation is successful.

In the next section, we will explain how to manipulate PowerPoint using classes and objects.

２. Basic of using python-pptx

In this section, we would like to explain the basic usage of python-pptx.

python-pptx follows an object-oriented style of writing code. Since it is object-oriented, it is necessary to always be aware of the hierarchical structure of objects, such as parent (Super) classes and child (Sub) classes.

Object hierarchical structure… It is a little difficult to understand, but just as the various elements that make up a PowerPoint file (slides, place folders, contents, etc.) have parent-child relationships (Fig2), objects that are program components also have parent-child relationships and are related to each other.

For example, the Root (top level) object is the Presentation object, which is the main body of the file, and below it is the Slide object, which manages each slide, and below that is the Shape object, which is the various types of content. (Fig3)

Details of each level are described below.

2.1 Create and Save Presentation

Python-pptx manages presentation file information as a Presentation object. Therefore, the first step is to obtain the Root (top-level) object, the Presentation object.

To retrieve the object, the Presentation class should be formatted as follows

Furthermore, depending on the purpose of editing/creation, there would be two patterns: (1) creating a new presentation, and (2) reading and editing an existing presentation (pptx file). The former specifies no arguments, and the latter specifies the name of the file to be read with its path.

When you have finished creating and editing your presentation, save it for the last time. To save a file, use the save() method in the following format.

The arg:file specifies the name of the file to be saved. To overwrite an existing file, specify the name of the loaded file. Note that overwrite saving does not specifically display a warning message.

An image of creating and saving a presentation is shown in Fig4 below.

2.2 Add and Get Slides (Slide Object)

Now that the Presentation object has been obtained, the next step is to add and obtain the slide (Slide object) that will serve as the foundation for the content.

The Presentation object manages all the slides that make up the file as the Slides collection(an iterable object whose elements are Slide objects).

Therefore, to add a new slide or retrieve an existing slide, you must first access the Slides collection (Fig5)

Slides Collection can be obtained with the slides property.(➀) Access to individual elements of a collection can be specified by index.(②) Also, use the add_slide() method to add a new slide. (➂) The format for each is as follows.

The arg:slide_layout of the add_slide() method is set to a SlideLayout object that is the template for the slide to be added.

The SlideLayout object can be obtained by using the slide_layouts property.

The SlideLayout object holds the layout template information as shown in <Fig.6><Table1>.

The desired object is obtained by specifying the index as in the following format.

There are 9 types of slide templates (place folders) pre-prepared in PowerPoint.

【SAMPLE (1)】

Let’s check what we have done so far with concrete sample codes.

The code summary is to create and save a presentation with only 3 template slides.<List1>

from pptx import Presentation

prs = Presentation()		# Obtaining a Presentation object

#---------------------------------------------------------------------------------------------------------------------------------------------------------------
title_slide_layout = prs.slide_layouts[0]	# Get the "Title and Slides" layout object
prs.slides.add_slide(title_slide_layout)	# Add new slide ("Title and Slide")

#---------------------------------------------------------------------------------------------------------------------------------------------------------------
two_title_layout = prs.slide_layouts[3]	# Get a "two-contents" layout object
prs.slides.add_slide(two_title_layout)	# Add new slide ("two content")

#---------------------------------------------------------------------------------------------------------------------------------------------------------------
comp_layout = prs.slide_layouts[4]	# Get layout object for "Comparison content"
prs.slides.add_slide(comp_layout)	# Add new slide ("Comparison Content")

#---------------------------------------------------------------------------------------------------------------------------------------------------------------
print(len(prs.slides)) 		# Number of elements in the collection of slide objects >>3

for slide in prs.slides:
    print(type(slide))			# Object type is Slide object >> <class 'pptx.slide.Slide'>
    print('slide_index [',prs.slides.index(slide), ']')		# Examine the index of the slide >> slide_index [ 0 ], slide_index [ 1 ], slide_index [ 2 ] 

#---------------------------------------------------------------------------------------------------------------------------------------------------------------
prs.save('List1_sample.pptx')	# Save as pptx file with name

The following is an explanation of key points.

In lines 1 and 3, the Presentation class is imported and objects are created, which will be handled by the variable “prs”.

The Len() function on line 14 checks the number of elements (3) in the Slides collection.

Finally, the save() method saves the file as named and outputs the pptx file.

The execution result of <List1> will be as follows.

A presentation file with three blank template (place folder) slides has been output. (Fig7)

2.3 Get Placeholder and Set Content

In the previous section, we specified a SlideLayout object, which is the template for adding slides. In this section, we will discuss a little deeper into the placeholder object, which is a component of the SlideLayout object.

The hierarchical structure of objects between the Slide object and the Placeholder object is shown in Fig8.

By default, there are a total of 19 types of place folders. Among them, the following are some of the most commonly used ones.

For example, the default template for PowerPoint consists of the following place folders. (The combination and arrangement can be freely changed in the master slide settings.(Fig9))

To edit an individual placeholder, you must retrieve the target placeholder object, which can be done with the placeholders property. Get all place folders on the slide, so you can select the object to be edited by specifying its index.

Placeholder objects are actually further classified into four types of objects depending on the content type (Text, Graph, Image, or Table).

The main properties common to these objects include the following.

In addition, object-specific methods include the following. Text, graphs, images, and tables can be inserted into the holder. <Fig.11>

【SAMPLE (2)】

Here is a concrete sample code that uses the Placeholder object.

The code outline will first create a new pptx file and add 2 slides. Next, after checking the attributes of the place folder in each slide, set the text to “TITLE“.

from pptx import Presentation

prs = Presentation()

#------------------------------------------------------------------------------------------------------
title_slide_layout = prs.slide_layouts[0]        # Get SlideLayout object for "Title and Slide"
sld0 = prs.slides.add_slide(title_slide_layout)  # Add new slide

for p in sld0.placeholders:  # Expand individual PlaceFolde objects in the slide
    print(p.name)  # Get the folder name
    # >>Title 1, Subtitle 2
    
    print(p.placeholder_format.idx, p.placeholder_format.type)  # Get the index and type
    # >>0 CENTER_TITLE (3), 1 SUBTITLE (4)

#------------------------------------------------------------------------------------------------------
title_slide_layout = prs.slide_layouts[3]        # Obtain a SlideLayout object with "Two contents"
sld1 = prs.slides.add_slide(title_slide_layout)  # Add new slide

for p in sld1.placeholders:  # Expand individual PlaceFolde objects in the slide
    print(p.name)  # Get folder name    
    # >>Title 1, Content Placeholder 2, Content Placeholder 3
    
    print(p.placeholder_format.idx, p.placeholder_format.type)  # Get the index and type
    # >>0 TITLE (1), 1 OBJECT (7), 2 OBJECT (7)

#------------------------------------------------------------------------------------------------------
title = sld0.placeholders[0]                     # Obtaining the PlaceFolder object for slide1, Title1.
title.text = "Slide Title and Slides"            # Set text

title = sld1.placeholders[0]                     # Obtaining the PlaceFolder object for Title1 on slide 2
title.text = "Slide Two Contents"

prs.save('List2_add_slide_save_file.pptx')

Now, let me explain the key points.

The execution result of <List2> is as follows

Two new slides (“Title and Slide” and “Two Contents”) were added and text was set for the title.

【SAMPLE (3)】

Here is one more sample code.

The code is outlined as follows. Load the output (pptx file) of <List2> and add a new slide (titled figure). And one that inserts the image into the “PICTURE” place folder, names it and saves it as.

Files (.pptx, .png) read by this program can be downloaded from

from pptx import Presentation

prs = Presentation('List2_add_slide_save_file.pptx')   # Load existing file
#------------------------------------------------------------------------------------------------------
title_slide_layout = prs.slide_layouts[8]                 # Get layout object for "Titled figure"
sld2 = prs.slides.add_slide(title_slide_layout)           # Add new slide
print(len(prs.slides))        # Number of slides >>3

for p in sld2.placeholders:   # Get the name of the place folder in the sheet
    print(p.name)             # >>Title 1　Picture Placeholder 2　Text Placeholder 3

#------------------------------------------------------------------------------------------------------
sld2.placeholders[0].text = 'Titled Image Slides'             
sld2.placeholders[1].insert_picture('Bussiness_Icon.png')  # Paste image into the Image Place folder
sld2.placeholders[2].text = 'Image has been pasted.'              

prs.save('List3_load_file_paste_image.pptx')              # Rename and save as

Let me explain the key points.

Check the name of the place folder included in the slide at the name property on lines 9 and 10. (TITLE, PICTURE, BODY)

The execution result of <List3> is as follows.

A new slide is added to the existing file and the image is inserted into the PICTURE folder.

3. Sumary

How was it?

In this article, we have explained the basics of using the “python-pptx library” to manipulate PowerPoint: “creating a presentation“, “adding slides“, and “creating content using the place folder“.

You have realized that this is all you need to create a minimal presentation file.

Finally, let’s keep in mind the main points of this article.

Now that you understand the basics of python-pptx, we will introduce “more practical use cases” from the following series.

In the next issue, we will show you how to insert text into PowerPoint.

The basic concept of PowerPoint is to create graphically appealing materials using figures and tables, but it is important to use “text” appropriately in areas where you want to emphasize and appeal, such as bullet points, conclusions, and supplementary text.

The following article summarizes such methods.

【Python×PowerPoint】Edit Text in Paragraph with python-pptx

To set and edit presentation(pptx) strings at a higher level, you need to be familiar with the "TextFrame object" and other related objects, methods, and attributes.

www.shibutan-bloomers.com

2022.06.04

Stay tuned for my next post!

Japanese is here >>

In addition to this PowerPoint, we also have a series of articles about libraries to manipulate “Excel” and “Word”. Let’s aim to improve work efficiency by using Python to manipulate the three major Office software!

〇 Click here for a series of articles on “Excel”.

【Python×Excel】Basic Usage of "openpy-xl" (Install ~ Book, Sheet, Cells)

This is an illustrated explanation of openpyxl, a library for manipulating Excel in Python. From how to install the library to "creating a new Workbook/Worksheet" and "manipulating rows, columns, and cells" are condensed in this one article.

www.shibutan-bloomers.com

2022.03.05

〇 Click here for a series of articles on “Word”.

【Python×Word】python-docxの導入~ドキュメント(段落・文章)作成までを徹底攻略

MS-OfficeのWordをPythonで操作する方法を紹介しています。今回は外部ライブラリ「python-docx」をとりあげます。Wordのメインコンテンツである「文章を作成する」について図解を用いて徹底的に解説します。

www.shibutan-bloomers.com

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Thank you for reading to the end.