Open Presentation

Besides creating PowerPoint presentations from scratch, Aspose.Slides allows you to open existing presentations. After you load a presentation, you can get information about the presentation, edit the presentation (content on its slides), add new slides or remove existing ones, etc.

Open Presentation

To open an existing presentation, you simply have to instantiate the Presentation class and pass the file path (of the presentation you want to open) to its constructor.

This Python code shows you how to open a presentation and also find out the number of slides it contains:

import aspose.slides as slides

# Instantiates the Presentation class and passes the file path to its constructor
with slides.Presentation("pres.pptx") as pres:
    # Prints the total number of slides present in the presentation
    print(pres.slides.length)

Open Password Protected Presentation

When you have to open a password-protected presentation, you can pass the password through the password property (from the LoadOptions class) to decrypt the presentation and load the presentation. This Python code demonstrates the operation:

import aspose.slides as slides

load_options = slides.LoadOptions()
load_options.password = "PASSWORD"
with slides.Presentation("pres.pptx", load_options) as pres:
    ...

Open Large Presentation

Aspose.Slides provides options (the blob_management_options property in particular) under the LoadOptions class to allow you to load large presentations.

This Python demonstrates an operation in which a large presentation (say 2GB in size) is loaded:

import aspose.slides as slides
import os

loadOptions = slides.LoadOptions()
loadOptions.blob_management_options = slides.BlobManagementOptions()
loadOptions.blob_management_options.presentation_locking_behavior = slides.PresentationLockingBehavior.KEEP_LOCKED

with slides.Presentation("pres.pptx", loadOptions) as pres:
    # The large presentation has been loaded and can be used, but the memory consumption is still low.

    # Makes changes to the presentation.
    pres.slides[0].name = "Very large presentation"

    # The presentation will be saved to the other file. The memory consumption stays low during the operation
    pres.save("veryLargePresentation-copy.pptx", slides.export.SaveFormat.PPTX)

    # can't do that! IO exception will be thrown because the file is locked while pres objects will
    # not be disposed
    os.remove("pres.pptx")

# It is ok to do it here. The source file is not locked by the pres object.
os.remove("pres.pptx")

Info

To circumvent certain limitations when interacting with streams, Aspose.Slides may copy the stream’s content. Loading a large presentation through its stream will result in the copying of the presentation’s contents and cause slow loading. Therefore, when you intend to load a large presentation, we strongly recommend that you use the presentation file path and not its stream.

When you want to create a presentation that contains large objects (video, audio, big images, etc.), you can use the Blob facility to reduce memory consumption.

Load Presentation

Aspose.Slides provides IResourceLoadingCallback with a single method to allow you to manage external resources. This Python code shows you how to use the IResourceLoadingCallback interface:

# [TODO[not_supported_yet]: python implementation of .net interfaces]

Open and Save Presentation

Steps: Open and Save Presentation in Python

Create an instance of the Presentation class and pass the file you want to open.
Save the presentation.

import aspose.slides as slides

# Instantiate a Presentation object that represents a PPT file
with slides.Presentation() as presentation:
    
    #...do some work here...

    # Save your presentation to a file
    presentation.save("Saved_out.pptx", slides.export.SaveFormat.PPTX)

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