解决“java not found and java_home environment variable is not set. install java and set java_home to point to the java installation directory.”，在Pycharm中正确配置pyspark
问题描述：
在pycharm中安装pyspark库，运行时，出现以下报错：
java not found and java_home environment variable is not set. install java and set java_home to point to the java installation directory.
Exception: Java gateway process exited before sending its port number
解决：
1.Anaconda Prompt中安装pyspark
2. 打开Pycharm，点击RUN---->Edit Configurations---->Configuration----->Environment---->Environment variables
点击+，输入变量名称及变量路径：
PYTHONPATH D:\ProgramData\Anaconda3\Lib\site-packages\pyspark\python
SPARK_HOME D:\ProgramData\Anaconda3\Lib\site-packages\pyspark
JAVA_HOME D:\ProgramData\Anaconda3\Lib\site-packages\pyspark\jars
3.保存，重新运行代码即可。