Fixes #314 - Delegate type coercion to openpyxl

Thanks Cristiano Lopes for the initial patch.

HISTORY.md

@@ -4,6 +4,8 @@
 
 - The project is now maintained by the Jazzband team, https://jazzband.co
 - Fixed `DataBook().load` parameter ordering (first stream, then format).
+- Fixed a regression for xlsx exports where non-string values were forced to
+  strings (#314).
 - Added search to all documentation pages
 - Open xlsx workbooks in read-only mode (#316)
 - Unpin requirements

tablib/formats/_xlsx.py

@@ -117,8 +117,6 @@ def dset_sheet(dataset, ws, freeze_panes=True):
 
             # bold headers
             if (row_number == 1) and dataset.headers:
-                # cell.value = unicode('%s' % col, errors='ignore')
-                cell.value = unicode(col)
                 cell.font = bold
                 if freeze_panes:
                     #  Export Freeze only after first Line
@@ -126,16 +124,18 @@ def dset_sheet(dataset, ws, freeze_panes=True):
 
             # bold separators
             elif len(row) < dataset.width:
-                cell.value = unicode('%s' % col, errors='ignore')
                 cell.font = bold
 
             # wrap the rest
             else:
                 try:
-                    if '\n' in col:
-                        cell.value = unicode('%s' % col, errors='ignore')
-                        cell.alignment = wrap_text
-                    else:
-                        cell.value = unicode('%s' % col, errors='ignore')
+                    str_col_value = unicode(col)
                 except TypeError:
-                    cell.value = unicode(col)
+                    str_col_value = ''
+                if '\n' in str_col_value:
+                    cell.alignment = wrap_text
+
+            try:
+                cell.value = col
+            except (ValueError, TypeError):
+                cell.value = unicode(col)

test_tablib.py

@@ -782,6 +782,25 @@ class TSVTests(BaseTestCase):
         self.assertEqual(tsv, self.founders.tsv)
 
 
+class XLSXTests(BaseTestCase):
+    def test_xlsx_import_set(self):
+        data.append(('string', 42, 21.55))
+        data.headers = ('string', 'integer', 'float')
+        _xlsx = data.xlsx
+        data.xlsx = _xlsx
+        self.assertEqual(data.dict[0]['string'], 'string')
+        self.assertEqual(data.dict[0]['integer'], 42)
+        self.assertEqual(data.dict[0]['float'], 21.55)
+
+    def test_xlsx_wrong_char(self):
+        """Bad characters are not silently ignored. We let the exception bubble up."""
+        from openpyxl.utils.exceptions import IllegalCharacterError
+
+        with self.assertRaises(IllegalCharacterError):
+            data.append(('string', b'\x0cf'))
+            data.xlsx
+
+
 class JSONTests(BaseTestCase):
     def test_json_format_detect(self):
         """Test JSON format detection."""