small cleanups

Author: topper-123

pandas/core/frame.py

@@ -990,7 +990,7 @@ def __repr__(self) -> str:
         Return a string representation for a particular DataFrame.
         """
         if self._info_repr():
-            buf = StringIO("")
+            buf = StringIO()
             self.info(buf=buf)
             return buf.getvalue()
 
@@ -1004,7 +1004,7 @@ def _repr_html_(self) -> str | None:
         Mainly for IPython notebook.
         """
         if self._info_repr():
-            buf = StringIO("")
+            buf = StringIO()
             self.info(buf=buf)
             # need to escape the <class>, should be the first line.
             val = buf.getvalue().replace("<", r"&lt;", 1)