Fix STYLE #49656: concat.py and merge.py (#49853)

* Fix concat.py

* #49656: update concat.py, fix merge.py

* #49656: update concat.py and merge.py

Author: bang128

pandas/core/internals/concat.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-import copy
+import copy as cp
 import itertools
 from typing import (
     TYPE_CHECKING,
@@ -691,7 +691,7 @@ def _trim_join_unit(join_unit: JoinUnit, length: int) -> JoinUnit:
     else:
         extra_block = join_unit.block
 
-        extra_indexers = copy.copy(join_unit.indexers)
+        extra_indexers = cp.copy(join_unit.indexers)
         extra_indexers[0] = extra_indexers[0][length:]
         join_unit.indexers[0] = join_unit.indexers[0][:length]
 

pandas/core/reshape/merge.py

@@ -3,7 +3,7 @@
 """
 from __future__ import annotations
 
-import copy
+import copy as cp
 import datetime
 from functools import partial
 import string
@@ -1637,7 +1637,7 @@ def get_join_indexers(
 
     lkey, rkey, count = _factorize_keys(lkey, rkey, sort=sort, how=how)
     # preserve left frame order if how == 'left' and sort == False
-    kwargs = copy.copy(kwargs)
+    kwargs = cp.copy(kwargs)
     if how in ("left", "right"):
         kwargs["sort"] = sort
     join_func = {