Using PPTXRenderer#

PPTXRenderer allows you to write python code inside a presentation and execute it like a script. The output is rendered as a new presentation. You can use the following types of python code inside the input template.

Simple python expressions#

You can write simple python expressions inside any text field which gets evaluated at render time.

For example, you can write {{{5.566*3.456}}} or {{{sum([1123, 123, 123, 4])}}}

Substituting variable values and function results#

You can write expressions like {{{variable_name}}} or function call like {{{my_function("arg")}}} in the presentation. These variables and functions should be passed in as arguments to the render function.

For example:

If there is a template ppt which contains {{{my_variable}}} in a text box, and there is a function call {{{calculate_square(my_variable)}}} in another (or same) text box. You can pass in the input like below.

from pptx_renderer import PPTXRenderer
p = PPTXRenderer("template.pptx")

def sqr(input):
    return input*input

p.render(
   "output.pptx",
   {
      "my_variable": 100,
      "calculate_square": sqr
   }
)

Inserting images#

You can replace shape placeholders with images using PPTXRenderer. To insert an image, create a rectangle shape which will define where the image should be placed and the boundaries of the image. Then insert a placeholder text in the format {{{path_to_image:image()}}} where path_to_image is a variable whose value is the path to the image to be inserted.

As you can see, image is a function. You can pass in the following arguments to the function. All of these are optional.

preserve_aspect_ratio: If set to True, the image will be resized to fit

the shape. If set to False, the image will be stretched to fit the shape.

Default is True.
remove_shape: If set to True, the shape will be removed after the image

is inserted. Default is True.
horizontal_alignment: The horizontal alignment of the image inside the shape.

Can be one of left, center, right. Default is left.
vertical_alignment: The vertical alignment of the image inside the shape.

Can be one of top, center, bottom. Default is top.

Inserting Videos#

Insert a video in the same height and width as the shape. The placeholder should evaluate to a path to the video file. The placeholder should be specified as {{{path_to_video:video()}}}.

remove_shape: If set to True, the shape will be removed after the image

is inserted. Default is True.

Inserting tables#

Similar to images, you can replace shape placeholders with tables. To create a table, create a rectangle shape which will define where the table should be placed. Then insert a placeholder text in the format {{{table_data:table()}}} where table_data is a variable whose value is a list of lists. Just like image, table is also a function. You can pass in the following arguments to the function. All of these are optional.

first_row: If set to True, the first row of the table will be treated

as the header row. Default is True.
first_column: If set to True, the first column of the table will be

treated as the header column. Default is False.
last_row: If set to True, the last row of the table will be treated

as the footer row. Default is False.
last_column: If set to True, the last column of the table will be

treated as the footer column. Default is False.
horizontal_banding: If set to True, the table will have horizontal

banding. Default is True.
vertical_banding: If set to True, the table will have vertical

banding. Default is False.
remove_shape: If set to True, the shape will be removed after the table

is inserted. Default is True.

Writing code in notes#

Apart from using python expressions inside text boxes, you can write more elaborate code inside the slide notes surrounded by triple back ticks followed by python keyword as shown below.

```python
# python code
```

The code inside this block will get executed before the slide is evaluated. So, for example, you can define a function side the notes like below.

```python
def doubler(input):
   return input*input
```

Then you can write {{{doubler(100)}}} inside one of the text boxes in the same slide or any slide which comes after this slide.

Custom plugins#

The image and table functions are implemented as plugins. You can write your own plugins and use them in the presentation. To write a plugin, do the following steps

Create a plugin function: Create a function which accepts one or more

arguments. The first argument will be the a dictionary containing the

following key, value pairs.

result: The result of the expression which was evaluated inside the

placeholder text. For example, if the placeholder text is {{{5*6}}},

the result will be 30.
shape: The shape object where the placeholder was found.
slide: The slide object where the shape was found.
slide_no: The slide number where the shape was found. (First slide is 0)
presentation: The presentation object where the slide was found.

The rest of the arguments will be passed in as arguments to the plugin function during execution.

For example, the image plugin function’s signature is as follows.

def image(
  context,
  preserve_aspect_ratio=True,
  remove_shape=True,
  horizontal_alignment="left",
  vertical_alignment="top",
)

and an example usage is as follows.

{{{path_to_image:image(preserve_aspect_ratio=True, horizontal_alignment="center")}}}

Register the plugin: Register the plugin function using the register_plugin

method of the PPTXRenderer class. The first argument to this method is the

name of the plugin. The second argument is the plugin function.

from pptx_renderer import PPTXRenderer
p = PPTXRenderer("template.pptx")

def multiplier(context, factor):
  """This is a plugin function which multiplies the input by a factor
  and sets the text of the shape to the result."""
  shape = context["shape"]
  result = context["result"]
  shape.text = str(result * factor)

p.register_plugin("multiplier", multiplier)

p.render(
  "output.pptx",
  {
    "my_variable": 100,
  }
)

Now you can use the plugin multiplier in the presentation like below.

{{{my_variable:multiplier(10)}}}