This section explains how to add a VBA file containing functions or macros to an XlsxWriter file.
An Excel xlsm
file is exactly the same as an xlsx
file except that is
contains an additional vbaProject.bin
file which contains functions and/or
macros. Excel uses a different extension to differentiate between the two file
formats since files containing macros are usually subject to additional
security checks.
The vbaProject.bin
file is a binary OLE COM container. This was the format
used in older xls
versions of Excel prior to Excel 2007. Unlike all of the
other components of an xlsx/xlsm file the data isn’t stored in XML
format. Instead the functions and macros as stored as a pre-parsed binary
format. As such it wouldn’t be feasible to define macros and create a
vbaProject.bin
file from scratch (at least not in the remaining lifespan
and interest levels of the author).
Instead a workaround is used to extract vbaProject.bin
files from existing
xlsm files and then add these to XlsxWriter files.
The vba_extract.py
utility is used to extract the vbaProject.bin
binary
from an Excel 2007+ xlsm file. The utility is included in the XlsxWriter
examples directory and is also installed as a standalone executable file:
$ vba_extract.py macro_file.xlsm
Extracted: vbaProject.bin
Once the vbaProject.bin
file has been extracted it can be added to the
XlsxWriter workbook using the add_vba_project()
method:
workbook.add_vba_project('./vbaProject.bin')
If the VBA file contains functions you can then refer to them in calculations
using write_formula()
:
worksheet.write_formula('A1', '=MyMortgageCalc(200000, 25)')
Excel files that contain functions and macros should use an xlsm
extension
or else Excel will complain and possibly not open the file:
workbook = xlsxwriter.Workbook('macros.xlsm')
It is also possible to assign a macro to a button that is inserted into a
worksheet using the insert_button()
method:
import xlsxwriter
# Note the file extension should be .xlsm.
workbook = xlsxwriter.Workbook('macros.xlsm')
worksheet = workbook.add_worksheet()
worksheet.set_column('A:A', 30)
# Add the VBA project binary.
workbook.add_vba_project('./vbaProject.bin')
# Show text for the end user.
worksheet.write('A3', 'Press the button to say hello.')
# Add a button tied to a macro in the VBA project.
worksheet.insert_button('B3', {'macro': 'say_hello',
'caption': 'Press Me',
'width': 80,
'height': 30})
workbook.close()
It may be necessary to specify a more explicit macro name prefixed by the workbook VBA name as follows:
worksheet.insert_button('B3', {'macro': 'ThisWorkbook.say_hello'})
See Example: Adding a VBA macro to a Workbook from the examples directory for a working example.
Note
Button is the only VBA Control supported by Xlsxwriter. Due to the large effort in implementation (1+ man months) it is unlikely that any other form elements will be added in the future.
VBA macros generally refer to workbook and worksheet objects. If the VBA
codenames aren’t specified then XlsxWriter will use the Excel defaults of
ThisWorkbook
and Sheet1
, Sheet2
etc.
If the macro uses other codenames you can set them using the workbook and
worksheet set_vba_name()
methods as follows:
# Note: set codename for workbook and any worksheets.
workbook.set_vba_name('MyWorkbook')
worksheet1.set_vba_name('MySheet1')
worksheet2.set_vba_name('MySheet2')
You can find the names that are used in the VBA editor or by unzipping the
xlsm
file and grepping the files. The following shows how to do that using
libxml’s xmllint
to format the XML for clarity:
$ unzip myfile.xlsm -d myfile
$ xmllint --format `find myfile -name "*.xml" | xargs` | grep "Pr.*codeName"
<workbookPr codeName="MyWorkbook" defaultThemeVersion="124226"/>
<sheetPr codeName="MySheet"/>
Note
This step is particularly important for macros created with non-English versions of Excel.
The XlsxWriter test suite contains several tests to ensure that this feature works and there is a working example as shown above. However, there is no guarantee that it will work in all cases. Some effort may be required and some knowledge of VBA will certainly help. If things don’t work out here are some things to try:
Start with a simple macro file, ensure that it works and then add complexity.
Check the code names that macros use to refer to the workbook and
worksheets (see the previous section above). In general VBA uses a code
name of ThisWorkbook
to refer to the current workbook and the sheet
name (such as Sheet1
) to refer to the worksheets. These are the
defaults used by XlsxWriter. If the macro uses other names, or the macro
was extracted from an non-English language version of Excel, then you can
specify these using the workbook and worksheet set_vba_name()
methods:
# Note: set codename for workbook and any worksheets.
workbook.set_vba_name('MyWorkbook')
worksheet1.set_vba_name('MySheet1')
worksheet2.set_vba_name('MySheet2')
Try to extract the macros from an Excel 2007 file. The method should work with macros from later versions (it was also tested with Excel 2010 macros). However there may be features in the macro files of more recent version of Excel that aren’t backward compatible.