simplify formatter

Author: TomAugspurger

pandas/core/arrays/base.py

@@ -675,37 +675,29 @@ def __repr__(self):
                                length=len(self),
                                dtype=self.dtype)
 
-    def _formatter(self, formatter=None):
-        # type: (Optional[ExtensionArrayFormatter]) -> Callable[[Any], str]
+    def _formatter(self, boxed=False):
+        # type: (bool) -> Callable[[Any], str]
         """Formatting function for scalar values.
 
-        This is used in the default '__repr__'. The formatting function
-        receives instances of your scalar type.
+        This is used in the default '__repr__'. The returned formatting
+        function receives instances of your scalar type.
 
         Parameters
         ----------
-        formatter: GenericArrayFormatter, optional
-            The formatter this array is being rendered with. When the array
-            is being rendered inside an Index, Series, or DataFrame, a
-            formatter will be provided. So if you want your objects to
-            render differently inside a Series from on its own, checking
-            with ``formatter is None`` is an option.
-
-            The default behavior depends on whether `formatter` is passed.
-
-            * When `formatter` is None, :func:`repr` is returned.
-            * When `formatter` is passed, ``formatter.formatter`` is used,
-              which falls back to :func:`repr` if that isn't specified.
-
-            In general, just returning :func:`repr` should be fine.
+        boxed: bool, default False
+            An indicated for whether or not your array is being printed
+            within a Series, DataFrame, or Index (True), or just by
+            itself (False). This may be useful if you want scalar values
+            to appear differently within a Series versus on its own (e.g.
+            quoted or not).
 
         Returns
         -------
         Callable[[Any], str]
             A callable that gets instances of the scalar type and
-            returns a string.
+            returns a string. By defult, :func:`repr` is used.
         """
-        return getattr(formatter, 'formatter', None) or repr
+        return repr
 
     def _formatting_values(self):
         # type: () -> np.ndarray

pandas/core/arrays/categorical.py

@@ -499,7 +499,7 @@ def _constructor(self):
     def _from_sequence(cls, scalars, dtype=None, copy=False):
         return Categorical(scalars, dtype=dtype)
 
-    def _formatter(self, formatter=None):
+    def _formatter(self, boxed=False):
         # backwards compat with old printing.
         return None
 

pandas/core/arrays/integer.py

@@ -264,14 +264,12 @@ def _from_sequence(cls, scalars, dtype=None, copy=False):
     def _from_factorized(cls, values, original):
         return integer_array(values, dtype=original.dtype)
 
-    def _formatter(self, formatter=None):
-        if formatter is None:
-            def fmt(x):
-                if isna(x):
-                    return 'NaN'
-                return str(x)
-            return fmt
-        return formatter.formatter
+    def _formatter(self, boxed=False):
+        def fmt(x):
+            if isna(x):
+                return 'NaN'
+            return str(x)
+        return fmt
 
     def __getitem__(self, item):
         if is_integer(item):

pandas/core/arrays/period.py

@@ -350,9 +350,9 @@ def to_timestamp(self, freq=None, how='start'):
     # --------------------------------------------------------------------
     # Array-like / EA-Interface Methods
 
-    def _formatter(self, formatter=None):
-        if formatter:
-            return formatter.formatter or str
+    def _formatter(self, boxed=False):
+        if boxed:
+            return str
         return "'{}'".format
 
     def __setitem__(

pandas/core/arrays/sparse.py

@@ -1738,15 +1738,13 @@ def __unicode__(self):
             fill=printing.pprint_thing(self.fill_value),
             index=printing.pprint_thing(self.sp_index))
 
-    def _formatter(self, formatter=None):
-        if formatter is None:
-            def fmt(x):
-                if isna(x) and isinstance(x, float):
-                    return 'NaN'
-                return str(x)
-
-            return fmt
-        return formatter.formatter
+    def _formatter(self, boxed=False):
+        def fmt(x):
+            if isna(x) and isinstance(x, float):
+                return 'NaN'
+            return str(x)
+
+        return fmt
 
 
 SparseArray._add_arithmetic_ops()