| # Licensed to the Apache Software Foundation (ASF) under one or more |
| # contributor license agreements. See the NOTICE file distributed with |
| # this work for additional information regarding copyright ownership. |
| # The ASF licenses this file to You 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. |
| |
| |
| """ |
| This is part of a minimal example of how to use pycarbon to read a dataset not created |
| with pycarbon. Generates a sample dataset from random data. |
| """ |
| |
| import os |
| import argparse |
| import random |
| from pyspark.sql import SparkSession, Row |
| from pyspark.sql.types import StructType, StructField, IntegerType |
| |
| NON_PYCARBON_SCHEMA = StructType([ |
| StructField("id", IntegerType(), True), |
| StructField("value1", IntegerType(), True), |
| StructField("value2", IntegerType(), True) |
| ]) |
| |
| |
| def row_generator(x): |
| """Returns a single entry in the generated dataset. Return a bunch of random values as an example.""" |
| return Row(id=x, value1=random.randint(-255, 255), value2=random.randint(-255, 255)) |
| |
| |
| def generate_dataset_with_normal_schema(output_url='file:///tmp/carbon_external_dataset'): |
| # """Creates an example dataset at output_url in Carbon format""" |
| spark = SparkSession.builder \ |
| .master('local') \ |
| .getOrCreate() |
| sc = spark.sparkContext |
| sc.setLogLevel('INFO') |
| |
| rows_count = 10 |
| rows_rdd = sc.parallelize(range(rows_count)) \ |
| .map(row_generator) |
| |
| spark.createDataFrame(rows_rdd) \ |
| .write \ |
| .mode('overwrite') \ |
| .save(path=output_url, format='carbon') |
| |
| |
| if __name__ == '__main__': |
| parser = argparse.ArgumentParser(description='Pycarbon Hello World Example I') |
| parser.add_argument('-pp', '--pyspark-python', type=str, default=None, |
| help='pyspark python env variable') |
| parser.add_argument('-pdp', '--pyspark-driver-python', type=str, default=None, |
| help='pyspark driver python env variable') |
| |
| args = parser.parse_args() |
| |
| if args.pyspark_python is not None and args.pyspark_driver_python is not None: |
| os.environ['PYSPARK_PYTHON'] = args.pyspark_python |
| os.environ['PYSPARK_DRIVER_PYTHON'] = args.pyspark_driver_python |
| elif 'PYSPARK_PYTHON' in os.environ.keys() and 'PYSPARK_DRIVER_PYTHON' in os.environ.keys(): |
| pass |
| else: |
| raise ValueError("please set PYSPARK_PYTHON and PYSPARK_DRIVER_PYTHON variables, " |
| "using cmd line -pp PYSPARK_PYTHON_PATH -pdp PYSPARK_DRIVER_PYTHON_PATH, " |
| "or set PYSPARK_PYTHON and PYSPARK_DRIVER_PYTHON in system env") |
| |
| generate_dataset_with_normal_schema() |