Fix bug with smaller change

Author: yuanx749

doc/source/whatsnew/v2.0.2.rst

@@ -48,7 +48,6 @@ Other
 ~~~~~
 - Raised a better error message when calling :func:`Series.dt.to_pydatetime` with :class:`ArrowDtype` with ``pyarrow.date32`` or ``pyarrow.date64`` type (:issue:`52812`)
 
-
 .. ---------------------------------------------------------------------------
 .. _whatsnew_202.contributors:
 

doc/source/whatsnew/v2.0.3.rst

@@ -14,6 +14,7 @@ including other versions of pandas.
 Fixed regressions
 ~~~~~~~~~~~~~~~~~
 - Fixed performance regression in merging on datetime-like columns (:issue:`53231`)
+- Fixed regression when :meth:`DataFrame.to_string` creates extra space for string dtypes (:issue:`52690`)
 - For external ExtensionArray implementations, restored the default use of ``_values_for_factorize`` for hashing arrays (:issue:`53475`)
 -
 

pandas/io/formats/format.py

@@ -1391,11 +1391,8 @@ def _format(x):
 
         fmt_values = []
         for i, v in enumerate(vals):
-            if not is_float_type[i] and leading_space or self.formatter is not None:
-                if leading_space:
-                    fmt_values.append(f" {_format(v)}")
-                else:
-                    fmt_values.append(f"{_format(v)}")
+            if (not is_float_type[i] or self.formatter is not None) and leading_space:
+                fmt_values.append(f" {_format(v)}")
             elif is_float_type[i]:
                 fmt_values.append(float_format(v))
             else:

pandas/tests/io/formats/test_format.py

@@ -2208,12 +2208,10 @@ def test_max_rows_fitted(self, length, min_rows, max_rows, expected):
 
     def test_no_extra_space(self):
         # GH 52690: Check that no extra space is given
-        # Expected Output
         col1 = "TEST"
         col2 = "PANDAS"
         col3 = "to_string"
         expected = f"{col1:<6s} {col2:<7s} {col3:<10s}"
-        # Testing
         df = DataFrame([{"col1": "TEST", "col2": "PANDAS", "col3": "to_string"}])
         d = {"col1": "{:<6s}".format, "col2": "{:<7s}".format, "col3": "{:<10s}".format}
         result = df.to_string(index=False, header=False, formatters=d)