The xlwings add-in is the preferred way to be able to use
UDFs. Note that you don’t need an add-in
if you just want to manipulate Excel from Python via xlwings.
The ribbon of the add-in is compatible with Excel >= 2007 on Windows and >= 2016 on Mac. You could, however, use the add-in with earlier versions but you would need to change the settings directly in the config file, see below. On Mac, all UDF related functionality is not available.
The add-in is password protected with the password
xlwings. For debugging or to add new extensions, you need
to unprotect it.
To install the add-in, it’s easiest to use the command line client:
xlwings addin install. Technically, this copies the add-in
from Python’s installation directory to Excel’s
XLSTART folder. If you encounter issues, then you can also download the
xlwings.xlam) from the GitHub Release page
(make sure you download the same version as the version of the Python package). Once downloaded, you can install the add-in
by going to
Developer > Excel Add-in > Browse. If you don’t see
Developer as tab in your ribbon, make sure to
activate the tab first under
File > Options > Customize Ribbon (Mac:
Cmd + , > Ribbon & Toolbar).
Then, to use
UDFs in a workbook, you need to set a reference to
xlwings in the VBA editor, see
Tools > References..., Mac: it’s on the lower left corner of the VBA editor). Note that when
you create a workbook via
xlwings quickstart, the reference is already set.
While the defaults will often work out-of-the box, you can change the global settings directly in the add-in:
Interpreter: This is the path to the Python interpreter. This works also with virtual or conda envs on Mac. If you use conda envs on Windows, then use
Conda Envbelow instead. Examples:
"/usr/local/bin/python3.5". An empty field defaults to
pythonwthat expects the interpreter to be set in the
PATHon Windows or
PYTHONPATH: If the source file of your code is not found, add the path here.
Conda Base: If you are on Windows and use a conda env, then type here the base name of your Anaconda or Miniconda installation, e.g.
%USERPROFILE%\Anaconda. NOTE that you need at least conda 4.6!
Conda Env: If you are on Windows and use a conda env, then type here the name of your conda env, e.g.
myenv. Note that this requires you to either leave the
Interpreterblank or set it to
UDF Modules: Names of Python modules (without .py extension) from which the UDFs are being imported. Separate multiple modules by “;”. Example:
UDF_MODULES = "common_udfs;myproject"The default imports a file in the same directory as the Excel spreadsheet with the same name but ending in
Debug UDFs: Check this box if you want to run the xlwings COM server manually for debugging, see Debugging.
Log File: Leave empty for default location (see below) or provide the full path, e.g. .
RunPython: Use UDF Server: Uses the same COM Server for RunPython as for UDFs. This will be faster, as the interpreter doesn’t shut down after each call.
Restart UDF Server: This shuts down the UDF Server/Python interpreter. It’ll be restarted upon the next function call.
If you use
Conda Base and
Conda Env with UDFs, you currently can’t hide the command prompt that pops up.
You can still control if the output is printed to the command prompt or not though by setting the
Global Config: Ribbon/Config File¶
The settings in the xlwings Ribbon are stored in a config file that can also be manipulated externally. The location is
.xlwings\xlwings.confin your user folder
- Mac Excel 2016:
# Mac Excel 2011:
The format is as follows (keys are uppercase):
Mac Excel 2011 users have to create and edit the config file manually under
~/.xlwings/xlwings.conf as the
ribbon is not supported.
Workbook Directory Config: Config file¶
The global settings of the Ribbon/Config file can be overridden for one or more workbooks by creating a
in the workbook’s directory.
Workbook Config: xlwings.conf Sheet¶
Workbook specific settings will override global (Ribbon) and workbook directory config files:
Workbook specific settings are set by listing the config key/value pairs in a sheet with the name
When you create a new project with
xlwings quickstart, it’ll already have such a sheet but you need to rename
xlwings.conf to make it active.
Alternative: Standalone VBA module¶
Sometimes it might be useful to run xlwings code without having to install an add-in first. To do so, you
need to use the
standalone option when creating a new project:
xlwings quickstart myproject --standalone.
This will add the content of the add-in as a single VBA module so you don’t need to set a reference to the add-in anymore.
It will still read in the settings from your
xlwings.conf if you don’t override them by using a sheet with the name
Log File default locations¶
These log files are used for the error pop-up windows:
- Mac with Excel 2011:
- Mac with Excel 2016: