paper-xlsxAPI referencecell.read_onlyopenpyxl.cell.read_onlypaper-xlsx 0.2.1 API referenceCopy MarkdownOpen EMPTY_CELL attributeEMPTY_CELL= EmptyCell() ClassEmptyCellReadOnlyCellMergedCellpaper-xlsx 0.2.1 API referenceEmptyCellpaper-xlsx 0.2.1 API reference