findspark.init() IndexError: list index out of range error

Question

When running the following in a Python 3.5 Jupyter environment I get the error below. Any ideas on what is causing it?

import findspark
findspark.init()

Error:

IndexError                                Traceback (most recent call
last) <ipython-input-20-2ad2c7679ebc> in <module>()
      1 import findspark
----> 2 findspark.init()
      3 
      4 import pyspark

/.../anaconda/envs/pyspark/lib/python3.5/site-packages/findspark.py in init(spark_home, python_path, edit_rc, edit_profile)
    132     # add pyspark to sys.path
    133     spark_python = os.path.join(spark_home, 'python')
--> 134     py4j = glob(os.path.join(spark_python, 'lib', 'py4j-*.zip'))[0]
    135     sys.path[:0] = [spark_python, py4j]
    136 

IndexError: list index out of range

Answer 1

This is most likely due to the SPARK_HOME environment variable not being set correctly on your system. Alternatively, you can just specify it when you're initialising findspark, like so:

import findspark
findspark.init('/path/to/spark/home')

After that, it should all work!