xlwings - Make Excel fly with Python!

xlwings is a BSD-licensed Python library that makes it easy to call Python from Excel and vice versa:

• Interact with Excel from Python using a syntax that is close to VBA yet Pythonic.
• Replace your VBA macros with Python code and still pass around your workbooks as easy as before.

xlwings fully supports NumPy arrays and Pandas DataFrames. It works with Microsoft Excel on Windows and Mac.

Note

xlwings is currently in an early stage. The API might change in backward incompatible ways.

Interact with Excel from Python

Writing/reading values to/from Excel and adding a chart is as easy as:

>>> from xlwings import Workbook, Sheet, Range, Chart
>>> wb = Workbook()  # Creates a connection with a new workbook
>>> Range('A1').value = 'Foo 1'
>>> Range('A1').value
'Foo 1'
>>> Range('A1').value = [['Foo 1', 'Foo 2', 'Foo 3'], [10.0, 20.0, 30.0]]
>>> Range('A1').table.value  # or: Range('A1:C2').value
[['Foo 1', 'Foo 2', 'Foo 3'], [10.0, 20.0, 30.0]]
>>> Sheet(1).name
'Sheet1'
>>> chart = Chart.add(source_data=Range('A1').table)

The Range and Chart objects as used above will refer to the active sheet of the current Workbook wb. Include the Sheet name like this:

Range('Sheet1', 'A1:C3').value
Range(1, (1,1), (3,3)).value  # index notation
Chart.add('Sheet1', source_data=Range('Sheet1', 'A1').table)

Qualify the Workbook additionally like this:

Range('Sheet1', 'A1', wkb=wb).value
Chart.add('Sheet1', wkb=wb, source_data=Range('Sheet1', 'A1', wkb=wb).table)
Sheet(1, wkb=wb).name

or simply set the current workbook first:

wb.set_current()
Range('Sheet1', 'A1').value
Chart.add('Sheet1', source_data=Range('Sheet1', 'A1').table)
Sheet(1).name

These commands also work seamlessly with NumPy arrays and Pandas DataFrames.

Call Python from Excel

If, for example, you want to fill your spreadsheet with standard normally distributed random numbers, your VBA code is just one line:

Sub RandomNumbers()
    RunPython ("import mymodule; mymodule.rand_numbers()")
End Sub

This essentially hands over control to mymodule.py:

import numpy as np
from xlwings import Workbook, Range

def rand_numbers():
    """ produces standard normally distributed random numbers with shape (n,n)"""
    wb = Workbook.caller()  # Creates a reference to the calling Excel file
    n = Range('Sheet1', 'B1').value  # Write desired dimensions into Cell B1
    rand_num = np.random.randn(n, n)
    Range('Sheet1', 'C3').value = rand_num

To make this run, just import the VBA module xlwings.bas in the VBA editor (Open the VBA editor with Alt-F11, then go to File > Import File... and import the xlwings.bas file. ). It can be found in the directory of your xlwings installation.

Note

Always instantiate the Workbook within the function that is called from Excel and not outside as global variable. Older versions of the docs/samples were showing the wrong approach.

Easy deployment

Deployment is really the part where xlwings shines:

• Just zip-up your Spreadsheet with your Python code and send it around. The receiver only needs to have an installation of Python with xlwings (and obviously all the other packages you're using).
• There is no need to install any Excel add-in.
• If this still sounds too complicated, just freeze your Python code into an executable and use RunFrozenPython instead of RunPython. This gives you a standalone version of your Spreadsheet tool without any dependencies (RunFrozenPython is currently only available on Windows).

Installation

The easiest way to install xlwings is via pip:

pip install xlwings

Alternatively it can be installed from source. From within the xlwings directory, execute:

python setup.py install

Dependencies

• Windows: pywin32

  On Windows, it is recommended to use one of the scientific Python distributions like Anaconda, WinPython or Canopy as they already include pywin32. Otherwise it needs to be installed from here.

• Mac: psutil, appscript

  On Mac, the dependencies are automatically being handled if xlwings is installed with pip. However, the Xcode command line tools need to be available. Mac OS X 10.4 (Tiger) or later is required. The recommended Python distribution for Mac is Anaconda.

Optional Dependencies

• NumPy
• Pandas

These packages are not required but highly recommended as NumPy arrays and Pandas DataFrames/Series play very nicely with xlwings.

Python version support

xlwings runs on Python 2.6-2.7 and 3.1-3.4

Links

• Homepage: http://xlwings.org
• Documentation: http://docs.xlwings.org
• Source Code: http://github.com/zoomeranalytics/xlwings