remove circular import (#39152)

Author: MarcoGorelli

pandas/core/generic.py

@@ -85,7 +85,6 @@
 from pandas.core.dtypes.inference import is_hashable
 from pandas.core.dtypes.missing import isna, notna
 
-import pandas as pd
 from pandas.core import arraylike, indexing, missing, nanops
 import pandas.core.algorithms as algos
 from pandas.core.arrays import ExtensionArray
@@ -106,6 +105,7 @@
 from pandas.core.internals import ArrayManager, BlockManager
 from pandas.core.missing import find_valid_index
 from pandas.core.ops import align_method_FRAME
+from pandas.core.reshape.concat import concat
 from pandas.core.shared_docs import _shared_docs
 from pandas.core.sorting import get_indexer_indexer
 from pandas.core.window import Expanding, ExponentialMovingWindow, Rolling, Window
@@ -5304,7 +5304,11 @@ def sample(
                         "when sampling from a Series."
                     )
 
-            weights = pd.Series(weights, dtype="float64")
+            if isinstance(self, ABCSeries):
+                func = self._constructor
+            else:
+                func = self._constructor_sliced
+            weights = func(weights, dtype="float64")
 
             if len(weights) != axis_length:
                 raise ValueError(
@@ -5890,7 +5894,7 @@ def astype(
             return self.copy()
 
         # GH 19920: retain column metadata after concat
-        result = pd.concat(results, axis=1, copy=False)
+        result = concat(results, axis=1, copy=False)
         result.columns = self.columns
         return result
 
@@ -6254,7 +6258,7 @@ def convert_dtypes(
                 )
                 for col_name, col in self.items()
             ]
-            result = pd.concat(results, axis=1, copy=False)
+            result = concat(results, axis=1, copy=False)
             return result
 
     # ----------------------------------------------------------------------
@@ -6532,10 +6536,8 @@ def replace(
 
             if isinstance(to_replace, (tuple, list)):
                 if isinstance(self, ABCDataFrame):
-                    from pandas import Series
-
                     return self.apply(
-                        Series._replace_single,
+                        self._constructor_sliced._replace_single,
                         args=(to_replace, method, inplace, limit),
                     )
                 self = cast("Series", self)