Why can't PySpark find py4j.java_gateway?

问题:

I installed Spark, ran the sbt assembly, and can open bin/pyspark with no problem. However, I am running into problems loading the pyspark module into ipython. I'm getting the following error:

In [1]: import pyspark
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-1-c15ae3402d12> in <module>()
----> 1 import pyspark

/usr/local/spark/python/pyspark/__init__.py in <module>()
     61
     62 from pyspark.conf import SparkConf
---> 63 from pyspark.context import SparkContext
     64 from pyspark.sql import SQLContext
     65 from pyspark.rdd import RDD

/usr/local/spark/python/pyspark/context.py in <module>()
     28 from pyspark.conf import SparkConf
     29 from pyspark.files import SparkFiles
---> 30 from pyspark.java_gateway import launch_gateway
     31 from pyspark.serializers import PickleSerializer, BatchedSerializer, UTF8Deserializer, \
     32     PairDeserializer, CompressedSerializer

/usr/local/spark/python/pyspark/java_gateway.py in <module>()
     24 from subprocess import Popen, PIPE
     25 from threading import Thread
---> 26 from py4j.java_gateway import java_import, JavaGateway, GatewayClient
     27
     28

ImportError: No module named py4j.java_gateway

回答1:

In my environment (using docker and the image sequenceiq/spark:1.1.0-ubuntu), I ran in to this. If you look at the pyspark shell script, you'll see that you need a few things added to your PYTHONPATH:

export PYTHONPATH=$SPARK_HOME/python/:$PYTHONPATH
export PYTHONPATH=$SPARK_HOME/python/lib/py4j-0.8.2.1-src.zip:$PYTHONPATH

That worked in ipython for me.

Update: as noted in the comments, the name of the py4j zip file changes with each Spark release, so look around for the right name.

回答2:

I solved this problem by adding some paths in .bashrc

export SPARK_HOME=/home/a141890/apps/spark
export PYTHONPATH=$SPARK_HOME/python/:$PYTHONPATH
export PYTHONPATH=$SPARK_HOME/python/lib/py4j-0.8.2.1-src.zip:$PYTHONPATH

After this, it never raise ImportError: No module named py4j.java_gateway.

回答3:

In Pycharm, before running above script, ensure that you have unzipped the py4j*.zip file. and add its reference in script sys.path.append("path to spark*/python/lib")

It worked for me.

回答4:

#/home/shubham/spark-1.6.2
import os
import sys
# Set the path for spark installation
# this is the path where you have built spark using sbt/sbt assembly
os.environ['SPARK_HOME'] = "/home/shubham/spark-1.6.2"
# os.environ['SPARK_HOME'] = "/home/jie/d2/spark-0.9.1"
# Append to PYTHONPATH so that pyspark could be found
sys.path.append("/home/shubham/spark-1.6.2/python")
sys.path.append("/home/shubham/spark-1.6.2/python/lib")
# sys.path.append("/home/jie/d2/spark-0.9.1/python")
# Now we are ready to import Spark Modules
try:
    from pyspark import SparkContext
    from pyspark import SparkConf`enter code here`
    print "Hey nice"
except ImportError as e:
    print ("Error importing Spark Modules", e)
sys.exit(1)

回答5:

Install pip module 'py4j'.

pip install py4j

I got this problem with Spark 2.1.1 and Python 2.7.x. Not sure if Spark stopped bundling this package in latest distributions. But installing py4j module solved the issue for me.