replace syntax with f-string (#30919)

Author: HH-MWB

pandas/core/arrays/period.py

@@ -298,11 +298,11 @@ def __arrow_array__(self, type=None):
                 if self.freqstr != type.freq:
                     raise TypeError(
                         "Not supported to convert PeriodArray to array with different"
-                        " 'freq' ({0} vs {1})".format(self.freqstr, type.freq)
+                        f" 'freq' ({self.freqstr} vs {type.freq})"
                     )
             else:
                 raise TypeError(
-                    "Not supported to convert PeriodArray to '{0}' type".format(type)
+                    f"Not supported to convert PeriodArray to '{type}' type"
                 )
 
         period_type = ArrowPeriodType(self.freqstr)

pandas/core/dtypes/common.py

@@ -194,12 +194,11 @@ def ensure_python_int(value: Union[int, np.integer]) -> int:
     """
     if not is_scalar(value):
         raise TypeError(f"Value needs to be a scalar value, was type {type(value)}")
-    msg = "Wrong type {} for value {}"
     try:
         new_value = int(value)
         assert new_value == value
     except (TypeError, ValueError, AssertionError):
-        raise TypeError(msg.format(type(value), value))
+        raise TypeError(f"Wrong type {type(value)} for value {value}")
     return new_value
 
 

pandas/core/dtypes/dtypes.py

@@ -435,12 +435,11 @@ def __eq__(self, other: Any) -> bool:
             return hash(self) == hash(other)
 
     def __repr__(self) -> str_type:
-        tpl = "CategoricalDtype(categories={data}ordered={ordered})"
         if self.categories is None:
             data = "None, "
         else:
             data = self.categories._format_data(name=type(self).__name__)
-        return tpl.format(data=data, ordered=self.ordered)
+        return f"CategoricalDtype(categories={data}ordered={self.ordered})"
 
     @staticmethod
     def _hash_categories(categories, ordered: Ordered = True) -> int:

pandas/core/frame.py

@@ -2431,7 +2431,7 @@ def _verbose_repr():
                 dtype = self.dtypes.iloc[i]
                 col = pprint_thing(col)
 
-                line_no = _put_str(" {num}".format(num=i), space_num)
+                line_no = _put_str(f" {i}", space_num)
                 count = ""
                 if show_counts:
                     count = counts.iloc[i]