don't use f-string, fix formatting issues

Author: tdamsma

pandas/core/generic.py

@@ -2249,7 +2249,7 @@ def to_excel(
         inf_rep="inf",
         verbose=True,
         freeze_panes=None,
-        table=None
+        table=None,
     ):
         df = self if isinstance(self, ABCDataFrame) else self.to_frame()
 
@@ -2273,7 +2273,7 @@ def to_excel(
             startcol=startcol,
             freeze_panes=freeze_panes,
             engine=engine,
-            table=None
+            table=None,
         )
 
     def to_json(

pandas/io/excel/_openpyxl.py

@@ -394,10 +394,11 @@ def _to_excel_range(cls, startrow, startcol, endrow, endcol):
         """Convert (zero based) numeric coordinates to excel range."""
         from openpyxl.utils.cell import get_column_letter
 
-        return (
-            f"{get_column_letter(startcol+1)}{startrow+1}"
-            ":"
-            f"{get_column_letter(endcol+1)}{endrow+1}"
+        return "%s%d:%s%d" % (
+            get_column_letter(startcol + 1),
+            startrow + 1,
+            get_column_letter(endcol + 1),
+            endrow + 1,
         )
 
     def write_cells(

pandas/io/excel/_xlsxwriter.py

@@ -283,4 +283,3 @@ def write_table(
         options = {"columns": columns, "name": table}
 
         wks.add_table(startrow, startcol, startrow + n_rows, startcol + n_cols, options)
-

pandas/tests/io/excel/test_writers.py

@@ -242,7 +242,7 @@ def test_excel_table_roundtrip_indexname(self, ext):
         df.index.name = "foo"
 
         with ensure_clean(ext) as pth:
-            df.to_excel(pth, header=True, table='Table1')
+            df.to_excel(pth, header=True, table="Table1")
 
             xf = ExcelFile(pth)
             result = pd.read_excel(xf, xf.sheet_names[0], index_col=0)