Instalei o Spark, executei o conjunto sbt e posso abrir o bin / pyspark sem nenhum problema. No entanto, estou com problemas para carregar o módulo pyspark no ipython. Estou recebendo o seguinte erro:

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