Saving File to Response Object with Python.NET

Aspose.Cells for Python via .NET enables dynamic file generation and direct delivery to client browsers. This article explains different approaches for saving files to response streams.

Saving File to Response Stream

XLS Files

import os
from aspose.cells import Workbook, XlsSaveOptions

# For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-.NET
# The path to the documents directory.
current_dir = os.path.dirname(os.path.abspath(__file__))
data_dir = os.path.join(current_dir, "data")

# Load your source workbook
workbook = Workbook()

Response = None  # This would typically come from a web framework in actual usage

if Response is not None:
    # Save in Excel2003 XLS format
    save_options = XlsSaveOptions()
    # Save workbook to response stream with appropriate headers
    workbook.save(Response, save_options)
    # Set content disposition and type for inline display
    Response.set_header("Content-Disposition", "inline; filename=\"output.xls\"")
    Response.set_content_type("application/vnd.ms-excel")
    Response.end()

Python.NET Equivalent:

XLSX Files

import os
from aspose.cells import Workbook, OoxmlSaveOptions
import io

# For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-.NET
current_dir = os.path.dirname(os.path.abspath(__file__))
data_dir = os.path.join(current_dir, "data")
Response = None

# Load your source workbook
workbook = Workbook()

if Response is not None:
    # Save in Xlsx format
    save_options = OoxmlSaveOptions()
    buffer = io.BytesIO()
    workbook.save(buffer, save_options)
    buffer.seek(0)
    Response.set_header('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet')
    Response.set_header('Content-Disposition', 'attachment; filename="output.xlsx"')
    Response.write(buffer.getvalue())
    Response.end()

Python.NET Equivalent:

# Using same approach as XLS example with different format
workbook.save(stream, SaveFormat.XLSX, ContentDisposition.INLINE, "report.xlsx")

PDF Files

import os
from aspose.cells import Workbook, PdfSaveOptions

# For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-.NET
# The path to the documents directory.
current_dir = os.path.dirname(os.path.abspath(__file__))
data_dir = os.path.join(current_dir, "data")
Response = None

# Creating a Workbook object
workbook = Workbook()

if Response is not None:
    # Save in Pdf format
    save_options = PdfSaveOptions()
    workbook.save(Response, os.path.join(data_dir, "output.pdf"), content_disposition="attachment")
    Response.end()

Python.NET Equivalent:

from Aspose.Cells import PdfSaveOptions

options = PdfSaveOptions()
workbook.save(stream, options, ContentDisposition.ATTACHMENT, "output.pdf")

Stream Handling in Python.NET

import os
from io import BytesIO
from aspose.cells import Workbook, SaveFormat
from fastapi import Response

async def download_excel():
    # For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-.NET
    current_dir = os.path.dirname(os.path.abspath(__file__))
    data_dir = os.path.join(current_dir, "data")
    file_path = os.path.join(data_dir, "Book1.xlsx")

    # Load your source workbook
    workbook = Workbook(file_path)
    
    # Save the workbook to a memory stream
    stream = BytesIO()
    workbook.save(stream, SaveFormat.XLSX)
    stream.seek(0)

    # Set the content type and file name
    content_type = "application/octet-stream"
    file_name = "output.xlsx"

    # Create response with headers
    headers = {"Content-Disposition": f"attachment; filename=\"{file_name}\""}
    return Response(
        content=stream.getvalue(),
        media_type=content_type,
        headers=headers
    )

Python.NET Implementation:

def save_to_response(workbook, filename, format):
    stream = MemoryStream()
    save_format = {
        "xls": SaveFormat.EXCEL_97_TO_2003,
        "xlsx": SaveFormat.XLSX,
        "pdf": SaveFormat.PDF
    }[format]
    
    workbook.save(stream, save_format)
    stream.seek(0)
    return stream.ToArray()

# Usage example:
# output = save_to_response(workbook, "report", "xlsx")
# HttpResponse(output, content_type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")

Important Notes:

1. Use MemoryStream for in-memory file generation
2. Always reset stream position with seek(0) before reading
3. Set appropriate MIME types in response headers
4. For web frameworks like Django/Flask, use framework-specific response handlers