Developer Guide

Aspose.Cells FOSS for Python is a free, open-source library for programmatic spreadsheet processing. Whether you are building data pipelines, generating automated reports, exporting ML results to Excel, or converting workbooks to Markdown for documentation pipelines, Aspose.Cells FOSS provides a comprehensive API that covers every layer of spreadsheet manipulation without requiring Microsoft Office.

Key Features

Workbook and Worksheet Operations

Create new workbooks from scratch or open existing XLSX or CSV files. Navigate the Workbook → Worksheets → Cells → Cell hierarchy with a clean, Pythonic API. Add, rename, and remove worksheets using workbook.add_worksheet(name) and workbook.remove_worksheet(index_or_name). Access individual cells by address (ws.cells["A1"]), set values directly, and iterate over populated ranges.

Cell Styling and Formatting

Apply granular formatting to individual cells. Control font family, size, color, bold, italic, underline, and strikethrough via the Font class. Set background fills using cell.style.fill.set_solid_fill("FFRRGGBB"). Colors are expressed as 8-character AARRGGBB hex strings without a # prefix (e.g., "FFFF0000" for opaque red).

Chart Creation and Visualization

Add column, line, bar, and pie charts to worksheets using dedicated methods such as ws.charts.add_bar(top_row, left_col, bottom_row, right_col) and ws.charts.add_line(...). Set the chart title as a string (chart.title = "My Chart"), configure category data at chart level (chart.category_data = "A2:A6"), and add named series (chart.n_series.add("B2:B6", category_data="A2:A6", name="Revenue")).

Formula Support

Enter Excel-compatible formulas by setting cell.formula = "=SUM(A1:A5)" or constructing a Cell(None, "=SUM(A1:A5)") and assigning it to the cells collection.

Multi-Format Export

Export workbooks to XLSX, CSV, TSV, Markdown, and JSON using a single workbook.save(path) call. Use SaveFormat constants for explicit control: SaveFormat.XLSX, SaveFormat.CSV, SaveFormat.TSV, SaveFormat.MARKDOWN, SaveFormat.JSON. Use MarkdownSaveOptions for fine-grained Markdown output (alignment, header level, worksheet index). Use MarkdownHandler.save_markdown_to_string(wb) for in-memory Markdown generation.

Note: Aspose.Cells FOSS exports to XLSX, CSV, TSV, Markdown, and JSON. PDF, HTML, PNG, TIFF, DOCX, and PPTX export are not part of the FOSS library.

Plugin Ecosystem

The official markitdown-aspose-cells-plugin package adds XLSX, XLS, and ODS support to Microsoft’s MarkItDown library. Install it with pip install markitdown-aspose-cells-plugin and use it transparently via the MarkItDown API.

Getting Started

Install 

pip install aspose-cells-foss

Hello World 

from aspose.cells_foss import Workbook, Cell

workbook = Workbook()
ws = workbook.worksheets[0]
ws.cells["A1"].value = "Hello, Aspose.Cells FOSS!"
ws.cells["A2"].value = 42
workbook.save("hello.xlsx")

Export to Markdown 

from aspose.cells_foss import Workbook, Cell

workbook = Workbook()
ws = workbook.worksheets[0]
ws.cells["A1"].value = "Name"
ws.cells["B1"].value = "Score"
ws.cells["A2"].value = "Alice"
ws.cells["B2"].value = 95
ws.cells["A3"].value = "Bob"
ws.cells["B3"].value = 88

workbook.save_as_markdown("results.md")

Create a Column Chart 

from aspose.cells_foss import Workbook, Cell

workbook = Workbook()
ws = workbook.worksheets[0]

data = [("Q1", 50), ("Q2", 100), ("Q3", 170), ("Q4", 300)]
for i, (label, value) in enumerate(data):
    ws.cells[f"A{i+2}"].value = label
    ws.cells[f"B{i+2}"].value = value

chart = ws.charts.add_bar(6, 0, 20, 8)
chart.title = "Quarterly Revenue"
chart.category_data = "A2:A5"
chart.n_series.add("B2:B5", category_data="A2:A5", name="Revenue")

workbook.save("chart.xlsx")

Style Cells 

from aspose.cells_foss import Workbook, Cell, Font

workbook = Workbook()
ws = workbook.worksheets[0]
ws.cells["A1"] = Cell("Revenue Report")

cell = ws.cells["A1"]
cell.style.font.bold = True
cell.style.font.size = 14
cell.style.font.color = "FFFFFFFF"   # White text (AARRGGBB, no #)
cell.style.fill.set_solid_fill("FF1E64C8")  # Blue background

workbook.save("styled.xlsx")

Available Guides

See Also