This tutorial shows how PDF and Python developers can add password protection to a PDF using the Aspose.PDF Cloud REST API, providing a clear, low‑code approach to secure your documents — see the format details on the PDF file info page.

Prerequisite

• Create an account API credentials to password protect the PDF
• Download the Aspose.PDF Cloud SDK for Python
• Set up a Python project and install the SDK

Steps to Password Protect PDF Doc using Python REST Interface

1. Import the required namespaces for Aspose PDF Cloud, file handling, and text encoding
2. Create a new PdfApi instance using your API key and App SID to authorize access to Aspose’s cloud services
3. Open your target PDF file from disk so you can read and process it
4. Convert your user and owner passwords into Base64 strings for secure transmission
5. Create a list of permissions—such as printing, extracting, and modifying content—that the encrypted PDF will allow
6. Call PutEncryptDocument to apply encryption to your file, specifying the output file name, encryption type, and the permissions list
7. After encryption, download the newly encrypted file from Aspose Cloud
8. Write the downloaded, encrypted content into a new file on your computer

These steps summarize the process to protect a PDF document using the Python‑based API: import the necessary classes, instantiate PdfApi, open the PDF, set user and owner passwords, define allowed permissions, invoke PutEncryptDocument, then download and save the protected file while checking the response status.

Code to Password Protect PDF Document using Python RESTful Service

The snippet demonstrates how to add a password to a PDF using the low‑code Python API. Remember to convert passwords to Base64 strings; otherwise, an exception will be thrown. You can extend the permissions list with options such as ModifyTextAnnotations, FillForm, ExtractContentWithDisabilities, AssembleDocument, and PrintingQuality.

For related tasks, see the article on Verify signature in PDF using Python REST API.