Xlsxwriter

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* Added support for background images in worksheets. See
:func:`set_background` and :ref:`ex_background`.

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* Added support for GIF image files (and in Excel 365, animated GIF files).

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* Added support for dynamic arrays and new Excel 365 functions like UNIQUE and
FILTER. See :func:`write_dynamic_array_formula`,
:ref:`formula_dynamic_arrays` and :ref:`ex_dynamic_arrays`.

* Added constructor option "use_future_functions" to enable newer Excel
"future" functions in Formulas. See :ref:`formula_future`, and the
:func:`Workbook` constructor.

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* Added fix for issue for where a y_axis font rotation of 0 was ignored.

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* Added option to set row heights and column widths in pixels via the
:func:`set_row_pixels` and :func:`set_column_pixels` methods.

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* Added ability to add accessibility options "description" and "decorative" to
images via :func:`insert_image`. :feature:`768`.

* Added fix for datetime.timedelta values that exceed the Excel 1900 leap day
(timedeltas greater than 59 days, in hours). This is a backward incompatible
change. :issue:`731`.

* Added the worksheet :func:`read_only_recommended` method to set the Excel
"Read-only Recommended" option that is available when saving a file.
:feature:`784`.

* Fixed issue where temp files used in `constant_memory` mode weren't
closed/deleted if the workbook object was garbage collected. :issue:`764`.

* Fixed issue where pattern formats without colors were given a default black
fill color. :issue:`790`.

* Added option to set a chart crossing to 'min' as well as the existing 'max'
option. The 'min' option isn't available in the Excel interface but can be
enabled via VBA. :feature:`773`.