Known Issues and Bugs

This section lists known issues and bugs and gives some information on how to submit bug reports.

Content is Unreadable. Open and Repair

Very, very occasionally you may see an Excel warning when opening an xlsxwriter file like:

Excel could not open file.xlsx because some content is unreadable. Do you want to open and repair this workbook.

This ominous sounding message is Excel’s default warning for any validation error in the XML used for the components of the XLSX file.

If you encounter an issue like this you should open an issue on GitHub with a program to replicate the issue (see below) or send one of the failing output files to the Author.

Formulas displayed as #NAME? until edited

Excel 2010 and 2013 added functions which weren’t defined in the original file specification. These functions are referred to as future functions. Examples of these functions are ACOT, CHISQ.DIST.RT , CONFIDENCE.NORM, STDEV.P, STDEV.S and WORKDAY.INTL. The full list is given in the MS XLSX extensions documentation on future functions.

When written using write_formula() these functions need to be fully qualified with the _xlfn. prefix as they are shown in the MS XLSX documentation link above. For example:

worksheet:write_formula('A1', '=_xlfn.STDEV.S(B1:B10)')

Formula results displaying as zero in non-Excel applications

Due to wide range of possible formulas and interdependencies between them, xlsxwriter doesn’t, and realistically cannot, calculate the result of a formula when it is written to an XLSX file. Instead, it stores the value 0 as the formula result. It then sets a global flag in the XLSX file to say that all formulas and functions should be recalculated when the file is opened.

This is the method recommended in the Excel documentation and in general it works fine with spreadsheet applications. However, applications that don’t have a facility to calculate formulas, such as Excel Viewer, or several mobile applications, will only display the 0 results.

If required, it is also possible to specify the calculated result of the formula using the optional value parameter in write_formula():

worksheet:write_formula('A1', '=2+2', num_format, 4)

Strings aren’t displayed in Apple Numbers in ‘constant_memory’ mode

In Workbook() 'constant_memory' mode xlsxwriter uses an optimisation where cell strings aren’t stored in an Excel structure call “shared strings” and instead are written “in-line”.

This is a documented Excel feature that is supported by most spreadsheet applications. One known exception is Apple Numbers for Mac where the string data isn’t displayed.

Images not displayed correctly in Excel 2001 for Mac and non-Excel applications

Images inserted into worksheets via insert_image() may not display correctly in Excel 2011 for Mac and non-Excel applications such as OpenOffice and LibreOffice. Specifically the images may looked stretched or squashed.

This is not specifically an xlsxwriter issue. It also occurs with files created in Excel 2007 and Excel 2010.

Reporting Bugs

Here are some tips on reporting bugs in xlsxwriter.

Upgrade to the latest version of the module

The bug you are reporting may already be fixed in the latest version of the module. You can check which version of xlsxwriter that you are using as follows:

lua -e 'W = require "xlsxwriter.workbook"; print(W.version)'

Check the Changes in XlsxWriter section to see what has changed in the latest versions.

Read the documentation

Read or search the xlsxwriter documentation to see if the issue you are encountering is already explained.

Look at the example programs

There are many Examples in the distribution. Try to identify an example program that corresponds to your query and adapt it to use as a bug report.

Use the xlsxwriter Issue tracker on GitHub

The xlsxwriter issue tracker is on GitHub.

Pointers for submitting a bug report

  1. Describe the problem as clearly and as concisely as possible.
  2. Include a sample program. This is probably the most important step. It is generally easier to describe a problem in code than in written prose.
  3. The sample program should be as small as possible to demonstrate the problem. Don’t copy and paste large non-relevant sections of your program.

A sample bug report is shown below. This format helps analyse and respond to the bug report more quickly.

Issue with SOMETHING

I am using xlsxwriter to do SOMETHING but it appears to do SOMETHING ELSE.

I am using Lua version X.Y and xlsxwriter x.y.z.

Here is some code that demonstrates the problem:

local Workbook = require "xlsxwriter.workbook"

local workbook  = Workbook:new("hello_world.xlsx")
local worksheet = workbook:add_worksheet()

worksheet:write("A1", "Hello world")