🐍 Python in Excel

📘 Start with the full guides

The long-form treatment of python in excel, with the reasoning the shorter pages assume.

• GuideUsing Python in ExcelWrite =PY formulas that analyse workbook data with pandas, return tables and charts to the grid, and fail clearly — plus where in-cell Python ends and a real automation script begins.

🛠️ Step-by-step how-tos

One task each, with code you can copy, run and adapt.

• How-toClean Data with pandas in Python in ExcelUse pandas inside Excel's =PY() cells to clean a messy table — trim text, fix types, drop duplicates, standardise categories — and return the cleaned table to the grid, with the calculation-order and output-mode rules that make it work.
• How-toForecast a Time Series with Python in ExcelUse Python in Excel to forecast monthly sales from a table in the workbook: pull the history with xl(), give it a proper monthly date index, fit a Holt-Winters model with statsmodels, return the forecast and a simple prediction band as a spilled range, chart it with matplotlib, and know the limits — cloud execution, recalculation and FORECAST.ETS as a formula-only alternative.
• How-toGet External Data into Python in Excel with Power QueryPython in Excel cannot read files or call the internet, so bring CSVs, databases and web data in with Power Query, then analyse them with xl() — tables versus connection-only queries, refresh order, parameters and size limits.
• How-toPlot Charts with matplotlib in Python in ExcelDraw matplotlib and seaborn charts inside a =PY cell, show them in the cell or floating over the grid, size them properly, and know when a native Excel chart is the better choice.
• How-toReference Cells, Ranges and Tables with xl() in Python in ExcelEverything a =PY cell knows about your workbook comes through xl(). Reference single cells, ranges with headers, Excel tables, other sheets, named ranges and Power Query results.
• How-toReturn DataFrames and Values from Python in Excel CellsA =PY cell returns its last expression, either as a Python object card or spilled into the grid as Excel values. Shape DataFrames for the grid, avoid #SPILL!, and chain cells without recomputing.
• How-toRun a Regression with Python in ExcelFit a multiple linear regression in a =PY cell with statsmodels: read a table with xl(), fit with a formula, return a tidy coefficient table to the grid, predict with intervals, check the residuals with a chart, and confirm the numbers against LINEST.

⚖️ Compare the options

Which tool or approach to pick, and why.

• ComparisonPython in Excel vs openpyxl and xlwingsPython in Excel runs code inside a cell; openpyxl and pandas write files from a script; xlwings drives the Excel application. Compare where each runs, what it can reach and which jobs it suits.

🔧 When it breaks

The errors this topic produces, with the cause explained rather than just the fix.

• FixFix Python in Excel ErrorsWhat #PYTHON!, #CALC!, #SPILL!, #BUSY!, #CONNECT!, #TIMEOUT!, #BLOCKED! and #UNKNOWN! mean in a =PY cell, how to read the Diagnostics pane, and the fix for each one.

🧭 Follow it through a track

Prefer an ordered route? These tracks cover python in excel along the way, in the order that builds on itself.

• 🌱Getting started10 of this topic's pages

🔗 Related topics

Subjects that keep turning up on the same pages as this one, most overlap first.