Use cudf::distinct in Python binding

python/cudf/cudf/_lib/cpp/sorting.pxd

@@ -20,12 +20,6 @@ cdef extern from "cudf/sorting.hpp" namespace "cudf" nogil:
         vector[libcudf_types.order] column_order,
         vector[libcudf_types.null_order] null_precedence) except +
 
-    cdef unique_ptr[table] stable_sort_by_key(
-        const table_view& values,
-        const table_view& keys,
-        vector[libcudf_types.order] column_order,
-        vector[libcudf_types.null_order] null_precedence) except +
-
     cdef unique_ptr[column] rank(
         column_view input_view,
         rank_method method,

python/cudf/cudf/_lib/cpp/stream_compaction.pxd

@@ -20,6 +20,7 @@ from cudf._lib.cpp.types cimport (
 cdef extern from "cudf/stream_compaction.hpp" namespace "cudf" \
         nogil:
     ctypedef enum duplicate_keep_option:
+        KEEP_ANY 'cudf::duplicate_keep_option::KEEP_ANY'
         KEEP_FIRST 'cudf::duplicate_keep_option::KEEP_FIRST'
         KEEP_LAST 'cudf::duplicate_keep_option::KEEP_LAST'
         KEEP_NONE 'cudf::duplicate_keep_option::KEEP_NONE'
@@ -33,7 +34,7 @@ cdef extern from "cudf/stream_compaction.hpp" namespace "cudf" \
         column_view boolean_mask
     ) except +
 
-    cdef unique_ptr[table] unique(
+    cdef unique_ptr[table] distinct(
         table_view source_table,
         vector[size_type] keys,
         duplicate_keep_option keep,

python/cudf/cudf/_lib/stream_compaction.pyx

@@ -9,22 +9,19 @@ from libcpp.vector cimport vector
 
 from cudf._lib.column cimport Column
 from cudf._lib.cpp.column.column_view cimport column_view
-from cudf._lib.cpp.sorting cimport stable_sort_by_key as cpp_stable_sort_by_key
 from cudf._lib.cpp.stream_compaction cimport (
     apply_boolean_mask as cpp_apply_boolean_mask,
+    distinct as cpp_distinct,
     distinct_count as cpp_distinct_count,
     drop_nulls as cpp_drop_nulls,
     duplicate_keep_option,
-    unique as cpp_unique,
 )
 from cudf._lib.cpp.table.table cimport table
 from cudf._lib.cpp.table.table_view cimport table_view
 from cudf._lib.cpp.types cimport (
     nan_policy,
     null_equality,
-    null_order,
     null_policy,
-    order,
     size_type,
 )
 from cudf._lib.utils cimport (
@@ -148,40 +145,13 @@ def drop_duplicates(list columns,
         else null_equality.UNEQUAL
     )
 
-    cdef vector[order] column_order = (
-        vector[order](
-            cpp_keys.size(),
-            order.ASCENDING
-        )
-    )
-    cdef vector[null_order] null_precedence = (
-        vector[null_order](
-            cpp_keys.size(),
-            null_order.BEFORE
-        )
-    )
-
     cdef table_view source_table_view = table_view_from_columns(columns)
-    cdef table_view keys_view = source_table_view.select(cpp_keys)
-    cdef unique_ptr[table] sorted_source_table
     cdef unique_ptr[table] c_result
 
     with nogil:
-        # cudf::unique keeps unique rows in each consecutive group of
-        # equivalent rows. To match the behavior of pandas.DataFrame.
-        # drop_duplicates, users need to stable sort the input first
-        # and then invoke cudf::unique.
-        sorted_source_table = move(
-            cpp_stable_sort_by_key(
-                source_table_view,
-                keys_view,
-                column_order,
-                null_precedence
-            )
-        )
         c_result = move(
-            cpp_unique(
-                sorted_source_table.get().view(),
+            cpp_distinct(
+                source_table_view,
                 cpp_keys,
                 cpp_keep_option,
                 cpp_nulls_equal