Passing class functions to PySpark RDD

问题

I have a class named some_class() in a Python file here:

/some-folder/app/bin/file.py

I am importing it to my code here:

/some-folder2/app/code/file2.py

By

import sys
sys.path.append('/some-folder/app/bin')
from file import some_class

clss = some_class()

I want to use this class's function named some_function in map of spark

sc.parallelize(some_data_iterator).map(lambda x: clss.some_function(x))

This is giving me an error :

No module named file

While class.some_function when I am calling it outside map function of pyspark i.e. normally but not in pySpark's RDD. I think this has something to do with pyspark. I have no idea where am I going wrong in this.

I tried broadcasting this class and still didn't work.

回答1:

All Python dependencies have to be either present on the search path of the worker nodes or distributed manually using SparkContext.addPyFile method so something like this should do the trick:

sc.addPyFile("/some-folder/app/bin/file.py")

It will copy the file to all the workers and place in the working directory.

On a side note please don't use file as module name, even if it is only an example. Shadowing built-in functions in Python is not a very good idea.

来源：https://stackoverflow.com/questions/32569633/passing-class-functions-to-pyspark-rdd