os.getenv返回空输出-python [英] os.getenv returns empty output - python

问题描述

我是python的新手，在执行os命令时遇到一些问题.

I am new to python and encountering some issues while executing os commands.

我已如下所示设置了environment variables

SPARK_HOME = '/opt/spark'
HAIL_HOME  = '/opt/hail/hail'

当我键入os.getenv('SPARK_HOME')时，我得到以下输出

When I type os.getenv('SPARK_HOME'), I get the below output

'/opt/spark/'

但是当我键入os.getenv('HAIL_HOME')时，会得到空白输出

But when I type os.getenv('HAIL_HOME'), I get blank output

请注意，我是使用jupyter笔记本从虚拟环境中键入上述两个命令的.

Please note that I type the above two commands from a virtual environment using jupyter notebook.

1. 为什么它适用于spark并为hail返回空

1. Why it works for spark and returns empty for hail

可以指导我解决这个问题吗?

Can guide me with this issue?

推荐答案

基于我们在聊天中的讨论，确定了几个问题.

Based on our discussion on chat, identified several issues.

变量设置与环境变量设置混淆.因此设置它们的正确方法应该是:

Variable setting is confused with env variable setting. So correct way to set them should be like:

os.putenv('SPARK_HOME', '/opt/spark')
os.putenv('HAIL_HOME', '/opt/hail/hail')

即使错误地尝试设置env变量，SPARK_HOME也会显示正确的值，因为jupyter进程会从shell继承该变量.

Even the mistaken env variable set attempts, SPARK_HOME shows the correct value because jupyter process inherits that variable from the shell.

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