apache-spark - 导入 Pyspark Delta Lake 模块时找不到模块错误

Question

我正在使用 delta lake 运行 Pyspark，但是当我尝试导入 delta 模块时，我得到一个 ModuleNotFoundError: No module named 'delta' .这是在一台没有互联网连接的机器上，所以我不得不从 Maven 手动下载 delta-core jar。并将其放入 %SPARK_HOME%/jars文件夹。

我的程序运行没有任何问题，我能够从 delta lake 写入和读取，所以我很高兴我得到了正确的 jar。但是当我尝试导入增量模块时 from delta.tables import *我收到错误。

有关信息，我的代码是:

import os
from pyspark.sql import SparkSession
from pyspark.sql.types import TimestampType, FloatType, StructType, StructField
from pyspark.sql.functions import input_file_name
from Constants import Constants

if __name__ == "__main__":
    constants = Constants()
    spark = SparkSession.builder.master("local[*]")\
                                .appName("Delta Lake Testing")\
                                .getOrCreate()

    # have to start spark session before importing: https://docs.delta.io/latest/quick-start.html#python
    from delta.tables import *

    # set logging level to limit output
    spark.sparkContext.setLogLevel("ERROR")

    spark.conf.set("spark.sql.session.timeZone", "UTC")
    # push additional python files to the worker nodes
    base_path = os.path.abspath(os.path.dirname(__file__))
    spark.sparkContext.addPyFile(os.path.join(base_path, 'Constants.py'))

    # start pipeline
    schema = StructType([StructField("Timestamp", TimestampType(), False),\
                        StructField("ParamOne", FloatType(), False),\
                        StructField("ParamTwo", FloatType(), False),\
                        StructField("ParamThree", FloatType(), False)])

    df = spark.readStream\
               .option("header", "true")\
               .option("timestampFormat", "yyyy-MM-dd HH:mm:ss")\
               .schema(schema)\
               .csv(constants.input_path)\
               .withColumn("input_file_name", input_file_name())

     df.writeStream\
       .format("delta")\
       .outputMode("append")\
       .option("checkpointLocation", constants.checkpoint_location)\
       .start("/tmp/bronze")

    # await on stream
    sqm = spark.streams
    sqm.awaitAnyTermination()

这是使用 Spark v2.4.4 和 Python v3.6.1，作业是使用 spark-submit path/to/job.py 提交的

Answer 1

%pyspark
sc.addPyFile("**LOCATION_OF_DELTA_LAKE_JAR_FILE**")
from delta.tables import *