How to Export a OneNote File to PDF in Python

Aspose.Note FOSS for Python enables programmatic PDF export of Microsoft OneNote .one section files without requiring Microsoft Office or any operating-system-level document converter. Export is handled by the Document.Save() method backed by the optional ReportLab PDF renderer.

Benefits

Server-friendly: runs on any OS, including headless Linux servers and CI/CD containers
Stream-capable: save directly to an io.BytesIO buffer, no temporary file needed
Free and open-source: MIT license

Prerequisites

PDF export requires the optional ReportLab dependency. Install it via the [pdf] extra:

pip install "aspose-note[pdf]"

If you already have aspose-note installed without the extra:

pip install --upgrade "aspose-note[pdf]"

Verify that ReportLab is available:

python -c "import reportlab; print(reportlab.Version)"

Step-by-Step Guide

Step 1: Install aspose-note with PDF Support

pip install "aspose-note[pdf]"

Confirm the install (PDF is an export-only format — the library produces PDF output from OneNote source files; the reverse direction is not supported):

from aspose.note import Document, SaveFormat
print("aspose-note is ready.")

Step 2: Load the OneNote File

from aspose.note import Document

doc = Document("MyNotes.one")

Step 3: Export the Entire Document to PDF

The simplest export, covering all pages with default settings:

from aspose.note import Document, SaveFormat

doc = Document("MyNotes.one")
doc.Save("output.pdf", SaveFormat.Pdf)
print("PDF saved to output.pdf")

Step 4: Use PdfSaveOptions

PdfSaveOptions lets you configure PDF export settings:

from aspose.note import Document
from aspose.note.saving import PdfSaveOptions

doc = Document("MyNotes.one")

opts = PdfSaveOptions()
doc.Save("output.pdf", opts)

Available PdfSaveOptions

Option	Type	Default	Description
`PageIndex`	`int`	`0`	Zero-based index of the first page to export (0 = first page)
`PageCount`	`int \| None`	`None`	Number of pages to export from `PageIndex`; `None` exports all remaining pages

Step 5: Export to an In-Memory Stream

Document.Save() accepts a binary stream directly: no temporary file needed:

import io
from aspose.note import Document, SaveFormat
from aspose.note.saving import PdfSaveOptions

doc = Document("MyNotes.one")

buf = io.BytesIO()
doc.Save(buf, PdfSaveOptions())
pdf_bytes = buf.getvalue()
print(f"PDF size: {len(pdf_bytes)} bytes")

Step 6: Batch Export Multiple Files

Process multiple .one files in a directory:

from pathlib import Path
from aspose.note import Document, SaveFormat

input_dir = Path("./onenote_files")
output_dir = Path("./pdf_output")
output_dir.mkdir(exist_ok=True)

for one_file in input_dir.glob("*.one"):
    doc = Document(str(one_file))
    out_path = output_dir / one_file.with_suffix(".pdf").name
    doc.Save(str(out_path), SaveFormat.Pdf)
    print(f"Exported: {one_file.name} -> {out_path.name}")

Common Issues and Fixes

1. ImportError: No module named ‘reportlab’

Cause: The [pdf] extra was not installed.

Fix:

pip install "aspose-note[pdf]"

2. UnsupportedSaveFormatException

Cause: A format other than SaveFormat.Pdf was used. Only SaveFormat.Pdf is implemented.

Fix: Always use SaveFormat.Pdf for export. Other formats are declared for API compatibility but raise UnsupportedSaveFormatException.

3. IncorrectPasswordException

Cause: The .one file is encrypted. Encrypted documents are not supported.

Fix: Use an unencrypted .one file. The commercial Aspose.Note product supports encryption.

4. FileNotFoundError

Cause: The input .one file path is incorrect.

Fix: Use pathlib.Path.exists() to validate before loading:

from pathlib import Path
from aspose.note import Document, SaveFormat

path = Path("MyNotes.one")
assert path.exists(), f"File not found: {path.resolve()}"
doc = Document(str(path))
doc.Save("output.pdf", SaveFormat.Pdf)

5. Output PDF is blank or empty

Cause: The .one file contains pages but no text content (only images or tables with no text). The PDF renderer produces pages based on what ReportLab can render from the DOM.

Fix: Verify page content before exporting:

from aspose.note import Document, RichText

doc = Document("MyNotes.one")
text_count = len(doc.GetChildNodes(RichText))
print(f"RichText nodes found: {text_count}")

Frequently Asked Questions

Which save formats are supported?

Only SaveFormat.Pdf is currently implemented. The SaveFormat enum has exactly one member: SaveFormat.Pdf.

Can I export to a stream instead of a file?

Yes. Document.Save() accepts any writable binary stream as its first argument:

import io
from aspose.note import Document, SaveFormat
from aspose.note.saving import PdfSaveOptions

doc = Document("MyNotes.one")
buf = io.BytesIO()
doc.Save(buf, PdfSaveOptions())
pdf_bytes = buf.getvalue()

Does export preserve page order?

Yes. Pages are exported in the same order they appear in the DOM (the order returned by iterating the Document).

Is PDF export available on Linux?

Yes. ReportLab and Aspose.Note FOSS for Python are both OS-independent.

Can I export a subset of pages?

Yes. Use PdfSaveOptions with PageIndex (zero-based start page) and PageCount (number of pages to export; None = all remaining) to export a subset of pages. Both fields are forwarded to the PDF exporter in v26.3.2.

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