Rewrite how string is formatted (for backwards compatibility)

Marco Gorelli · Marco Gorelli · commit c4f07868a655 · 2019-08-20T10:25:21.000+01:00
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
@@ -6239,7 +6239,7 @@ def explode(self, column: Union[str, Tuple]) -> "DataFrame":
 
         if isinstance(self.index, MultiIndex):
             index_names = [
-                f"level_{num}" if val is None else val
+                "level_{num}".format(num=num) if val is None else val
                 for num, val in enumerate(self.index.names)
             ]
         else:

Original file line number	Diff line number	Diff line change
`@@ -6239,7 +6239,7 @@ def explode(self, column: Union[str, Tuple]) -> "DataFrame":`
`6239`	`6239`
`6240`	`6240`	`if isinstance(self.index, MultiIndex):`
`6241`	`6241`	`index_names = [`
`6242`		`- f"level_{num}" if val is None else val`
	`6242`	`+ "level_{num}".format(num=num) if val is None else val`
`6243`	`6243`	`for num, val in enumerate(self.index.names)`
`6244`	`6244`	`]`
`6245`	`6245`	`else:`