Add pct_change function for Series

CHANGELOG.md

@@ -166,6 +166,7 @@
 - Fixing empty null lists throwing explode_outer for a loop. ([#7649](https://github.com/rapidsai/cudf/pull/7649)) [@hyperbolic2346](https://github.com/hyperbolic2346)
 - Fix internal compiler error during JNI Docker build ([#7645](https://github.com/rapidsai/cudf/pull/7645)) [@jlowe](https://github.com/jlowe)
 - Fix Debug build break with device_uvectors in grouped_rolling.cu ([#7633](https://github.com/rapidsai/cudf/pull/7633)) [@mythrocks](https://github.com/mythrocks)
+- Parquet reader: Fix issue when using skip_rows on non-nested columns containing nulls ([#7627](https://github.com/rapidsai/cudf/pull/7627)) [@nvdbaranec](https://github.com/nvdbaranec)
 - Parquet reader:  Fix issue when using skip_rows on non-nested columns containing nulls ([#7627](https://github.com/rapidsai/cudf/pull/7627)) [@nvdbaranec](https://github.com/nvdbaranec)
 - Fix ORC reader for empty DataFrame/Table ([#7624](https://github.com/rapidsai/cudf/pull/7624)) [@rgsl888prabhu](https://github.com/rgsl888prabhu)
 - Fix specifying GPU architecture in JNI build ([#7612](https://github.com/rapidsai/cudf/pull/7612)) [@jlowe](https://github.com/jlowe)
@@ -265,6 +266,7 @@
 - Add groupby scan operations (sort groupby) ([#7387](https://github.com/rapidsai/cudf/pull/7387)) [@karthikeyann](https://github.com/karthikeyann)
 - Add cudf::explode_position ([#7376](https://github.com/rapidsai/cudf/pull/7376)) [@hyperbolic2346](https://github.com/hyperbolic2346)
 - Add string conversion to/from decimal values libcudf APIs ([#7364](https://github.com/rapidsai/cudf/pull/7364)) [@davidwendt](https://github.com/davidwendt)
+- Add groupby SUM_OF_SQUARES support ([#7362](https://github.com/rapidsai/cudf/pull/7362)) [@karthikeyann](https://github.com/karthikeyann)
 - Add  groupby SUM_OF_SQUARES support ([#7362](https://github.com/rapidsai/cudf/pull/7362)) [@karthikeyann](https://github.com/karthikeyann)
 - Add `Series.drop` api ([#7304](https://github.com/rapidsai/cudf/pull/7304)) [@isVoid](https://github.com/isVoid)
 - get_json_object() implementation ([#7286](https://github.com/rapidsai/cudf/pull/7286)) [@nvdbaranec](https://github.com/nvdbaranec)
@@ -273,6 +275,7 @@
 - Add support for special tokens in nvtext::subword_tokenizer ([#7254](https://github.com/rapidsai/cudf/pull/7254)) [@davidwendt](https://github.com/davidwendt)
 - Fix inplace update of data and add Series.update ([#7201](https://github.com/rapidsai/cudf/pull/7201)) [@galipremsagar](https://github.com/galipremsagar)
 - Implement `cudf::group_by` (hash) for `decimal32` and `decimal64` ([#7190](https://github.com/rapidsai/cudf/pull/7190)) [@codereport](https://github.com/codereport)
+- Adding support to specify "level" parameter for `Dataframe.rename` ([#7135](https://github.com/rapidsai/cudf/pull/7135)) [@skirui-source](https://github.com/skirui-source)
 - Adding support to specify "level" parameter  for `Dataframe.rename` ([#7135](https://github.com/rapidsai/cudf/pull/7135)) [@skirui-source](https://github.com/skirui-source)
 
 ## 🛠️ Improvements
@@ -413,6 +416,7 @@
 - Adding Interval Dtype ([#6984](https://github.com/rapidsai/cudf/pull/6984)) [@marlenezw](https://github.com/marlenezw)
 - Cleaning up `for` loops with `make_(counting_)transform_iterator` ([#6546](https://github.com/rapidsai/cudf/pull/6546)) [@codereport](https://github.com/codereport)
 
+
 # cuDF 0.18.0 (24 Feb 2021)
 
 ## Breaking Changes 🚨

cpp/CMakeLists.txt

@@ -28,7 +28,7 @@ elseif(CMAKE_CUDA_ARCHITECTURES STREQUAL "")
   set(CUDF_BUILD_FOR_DETECTED_ARCHS TRUE)
 endif()
 
-project(CUDF VERSION 21.06.00 LANGUAGES C CXX)
+project(CUDF VERSION 21.06.01 LANGUAGES C CXX)
 
 # Needed because GoogleBenchmark changes the state of FindThreads.cmake,
 # causing subsequent runs to have different values for the `Threads::Threads` target.

cpp/doxygen/Doxyfile

@@ -38,7 +38,7 @@ PROJECT_NAME           = "libcudf"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 21.06.00
+PROJECT_NUMBER         = 21.06.01
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a

cpp/libcudf_kafka/CMakeLists.txt

@@ -15,7 +15,7 @@
 #=============================================================================
 cmake_minimum_required(VERSION 3.18 FATAL_ERROR)
 
-project(CUDA_KAFKA VERSION 21.06.00 LANGUAGES CXX)
+project(CUDA_KAFKA VERSION 21.06.01 LANGUAGES CXX)
 
 ###################################################################################################
 # - Build options

docs/cudf/source/conf.py

@@ -79,7 +79,7 @@
 # The short X.Y version.
 version = '21.06'
 # The full version, including alpha/beta/rc tags.
-release = '21.06.00'
+release = '21.06.01'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.

java/src/main/native/CMakeLists.txt

@@ -32,7 +32,7 @@ elseif(CMAKE_CUDA_ARCHITECTURES STREQUAL "")
   set(CUDF_JNI_BUILD_FOR_DETECTED_ARCHS TRUE)
 endif()
 
-project(CUDF_JNI VERSION 21.06.00 LANGUAGES C CXX)
+project(CUDF_JNI VERSION 21.06.01 LANGUAGES C CXX)
 
 ###################################################################################################
 # - build options ---------------------------------------------------------------------------------

python/cudf/cudf/core/series.py

@@ -6014,6 +6014,42 @@ def explode(self, ignore_index=False):
 
         return super()._explode(self._column_names[0], ignore_index)
 
+    def pct_change(
+        self, periods=1, fill_method="ffill", limit=None, freq=None
+    ):
+        """
+        Calculates the percent change between sequential elements
+        in the Series.
+
+        Parameters
+        ----------
+        periods : int, default 1
+            Periods to shift for forming percent change.
+        fill_method : str, default 'ffill'
+            How to handle NAs before computing percent changes.
+        limit : int, optional
+            The number of consecutive NAs to fill before stopping.
+            Not yet implemented.
+        freq : str, optional
+            Increment to use from time series API.
+            Not yet implemented.
+
+        Returns
+        -------
+        Series
+        """
+        if limit is not None:
+            raise NotImplementedError("limit parameter not supported yet.")
+        if freq is not None:
+            raise NotImplementedError("freq parameter not supported yet.")
+        if fill_method not in ["ffill", "bfill"]:
+            raise ValueError("fill_method must be either 'ffill' or 'bfill'.")
+
+        data = self.fillna(method=fill_method, limit=limit)
+        diff = data.diff(periods=periods)
+        change = diff / data.shift(periods=periods, freq=freq)
+        return change
+
 
 class DatetimeProperties(object):
     """

python/cudf/cudf/tests/test_stats.py

@@ -316,6 +316,32 @@ def test_series_median(dtype, num_na):
         np.testing.assert_approx_equal(actual, desired)
 
 
+@pytest.mark.parametrize(
+    "data",
+    [
+        np.random.normal(-100, 100, 1000),
+        np.random.randint(-50, 50, 1000),
+        np.zeros(100),
+        np.array([1.123, 2.343, np.nan, 0.0]),
+        np.array([-2, 3.75, 6, None, None, None, -8.5, None, 4.2]),
+        cudf.Series([]),
+        cudf.Series([-3]),
+    ],
+)
+@pytest.mark.parametrize("periods", range(-5, 5))
+@pytest.mark.parametrize("fill_method", ["ffill", "bfill"])
+def test_series_pct_change(data, periods, fill_method):
+    cs = cudf.Series(data)
+    ps = cs.to_pandas()
+
+    if np.abs(periods) <= len(cs):
+        got = cs.pct_change(periods=periods, fill_method=fill_method)
+        expected = ps.pct_change(periods=periods, fill_method=fill_method)
+        np.testing.assert_array_almost_equal(
+            got.to_array(fillna="pandas"), expected
+        )
+
+
 @pytest.mark.parametrize(
     "data1",
     [