text: #! /usr/bin/env python
  # Copyright (c) 2020 Uber Technologies, Inc.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  # ==============================================================================
  
  from abc import ABC, abstractmethod
  
  
  class DataFrameEngine(ABC):
      @abstractmethod
      def df_like(self, df, proc_cols):
          raise NotImplementedError()
  
      @abstractmethod
      def parallelize(self, data):
          raise NotImplementedError()
  
      @abstractmethod
      def persist(self, data):
          raise NotImplementedError()
  
      @abstractmethod
      def compute(self, data):
          raise NotImplementedError()
  
      @abstractmethod
      def from_pandas(self, df):
          raise NotImplementedError()
  
      @abstractmethod
      def map_objects(self, series, map_fn, meta=None):
          raise NotImplementedError()
  
      @abstractmethod
      def map_partitions(self, series, map_fn, meta=None):
          raise NotImplementedError()
  
      @abstractmethod
      def apply_objects(self, series, map_fn, meta=None):
          raise NotImplementedError()
  
      @abstractmethod
      def reduce_objects(self, series, reduce_fn):
          raise NotImplementedError()
  
      @abstractmethod
      def to_parquet(self, df, path):
          raise NotImplementedError()
  
      @property
      @abstractmethod
      def array_lib(self):
          raise NotImplementedError()
  
      @property
      @abstractmethod
      def df_lib(self):
          raise NotImplementedError()
  
      @property
      @abstractmethod
      def partitioned(self):
          raise NotImplementedError()
  
      @abstractmethod
      def set_parallelism(self, parallelism):
          raise NotImplementedError()
  