None replace

Author: Ruchita Deshmukh

pandas/_libs/algos.pyx

@@ -463,6 +463,7 @@ def pad_inplace(algos_t[:] values,
                 continue
             fill_count += 1
             values[i] = val
+
         else:
             fill_count = 0
             val = values[i]

pandas/core/frame.py

@@ -4193,6 +4193,7 @@ def replace(
         limit=None,
         regex=False,
         method="pad",
+        replace_by_none=False
     ):
         return super().replace(
             to_replace=to_replace,
@@ -4201,6 +4202,7 @@ def replace(
             limit=limit,
             regex=regex,
             method=method,
+            replace_by_none=replace_by_none
         )
 
     @Appender(_shared_docs["shift"] % _shared_doc_kwargs)