REF: get regex logic out of Block.replace (#44932)

Author: jbrockmendel

pandas/core/generic.py

@@ -118,6 +118,7 @@
     nanops,
 )
 import pandas.core.algorithms as algos
+from pandas.core.array_algos.replace import should_use_regex
 from pandas.core.arrays import ExtensionArray
 from pandas.core.base import PandasObject
 import pandas.core.common as com
@@ -6688,9 +6689,17 @@ def replace(
                     return self._replace_columnwise(mapping, inplace, regex)
 
                 elif not is_list_like(value):  # NA -> 0
-                    new_data = self._mgr.replace(
-                        to_replace=to_replace, value=value, inplace=inplace, regex=regex
-                    )
+                    regex = should_use_regex(regex, to_replace)
+                    if regex:
+                        new_data = self._mgr.replace_regex(
+                            to_replace=to_replace,
+                            value=value,
+                            inplace=inplace,
+                        )
+                    else:
+                        new_data = self._mgr.replace(
+                            to_replace=to_replace, value=value, inplace=inplace
+                        )
                 else:
                     raise TypeError(
                         f'Invalid "to_replace" type: {repr(type(to_replace).__name__)}'

pandas/core/internals/array_manager.py

@@ -413,11 +413,17 @@ def _convert(arr):
 
         return self.apply(_convert)
 
-    def replace(self: T, value, **kwargs) -> T:
+    def replace_regex(self: T, **kwargs) -> T:
+        return self.apply_with_block("_replace_regex", **kwargs)
+
+    def replace(self: T, to_replace, value, inplace: bool) -> T:
+        inplace = validate_bool_kwarg(inplace, "inplace")
         assert np.ndim(value) == 0, value
         # TODO "replace" is right now implemented on the blocks, we should move
         # it to general array algos so it can be reused here
-        return self.apply_with_block("replace", value=value, **kwargs)
+        return self.apply_with_block(
+            "replace", value=value, to_replace=to_replace, inplace=inplace
+        )
 
     def replace_list(
         self: T,

pandas/core/internals/blocks.py

@@ -640,14 +640,11 @@ def replace(
         to_replace,
         value,
         inplace: bool = False,
-        regex: bool = False,
     ) -> list[Block]:
         """
         replace the to_replace value with value, possible to create new
-        blocks here this is just a call to putmask. regex is not used here.
-        It is used in ObjectBlocks.  It is here for API compatibility.
+        blocks here this is just a call to putmask.
         """
-        inplace = validate_bool_kwarg(inplace, "inplace")
 
         # Note: the checks we do in NDFrame.replace ensure we never get
         #  here with listlike to_replace or value, as those cases
@@ -661,11 +658,6 @@ def replace(
             blk.values._replace(to_replace=to_replace, value=value, inplace=True)
             return [blk]
 
-        regex = should_use_regex(regex, to_replace)
-
-        if regex:
-            return self._replace_regex(to_replace, value, inplace=inplace)
-
         if not self._can_hold_element(to_replace):
             # We cannot hold `to_replace`, so we know immediately that
             #  replacing it is a no-op.
@@ -691,13 +683,12 @@ def replace(
                 to_replace=to_replace,
                 value=value,
                 inplace=True,
-                regex=regex,
             )
 
         else:
             # split so that we only upcast where necessary
             return self.split_and_operate(
-                type(self).replace, to_replace, value, inplace=True, regex=regex
+                type(self).replace, to_replace, value, inplace=True
             )
 
     @final
@@ -756,10 +747,14 @@ def replace_list(
         values = self.values
 
         # TODO: dont special-case Categorical
-        if isinstance(values, Categorical) and len(algos.unique(dest_list)) == 1:
+        if (
+            isinstance(values, Categorical)
+            and len(algos.unique(dest_list)) == 1
+            and not regex
+        ):
             # We likely got here by tiling value inside NDFrame.replace,
             #  so un-tile here
-            return self.replace(src_list, dest_list[0], inplace, regex)
+            return self.replace(src_list, dest_list[0], inplace)
 
         # Exclude anything that we know we won't contain
         pairs = [
@@ -866,7 +861,7 @@ def _replace_coerce(
                         convert=False,
                         mask=mask,
                     )
-                return self.replace(to_replace, value, inplace=inplace, regex=False)
+                return self.replace(to_replace, value, inplace=inplace)
         return [self]
 
     # ---------------------------------------------------------------------

pandas/core/internals/managers.py

@@ -432,12 +432,18 @@ def convert(
             timedelta=timedelta,
         )
 
-    def replace(self: T, to_replace, value, inplace: bool, regex: bool) -> T:
-        assert np.ndim(value) == 0, value
+    def replace(self: T, to_replace, value, inplace: bool) -> T:
+        inplace = validate_bool_kwarg(inplace, "inplace")
+        # NDFrame.replace ensures the not-is_list_likes here
+        assert not is_list_like(to_replace)
+        assert not is_list_like(value)
         return self.apply(
-            "replace", to_replace=to_replace, value=value, inplace=inplace, regex=regex
+            "replace", to_replace=to_replace, value=value, inplace=inplace
         )
 
+    def replace_regex(self, **kwargs):
+        return self.apply("_replace_regex", **kwargs)
+
     def replace_list(
         self: T,
         src_list: list[Any],