Python Get System Environment Variable Linux

Question

I've exposed one system environment variable say KEY1 with value VALUE1 in /etc/profile (I know, I know, it's probably bad)

Now in my shell if I do

$ echo $KEY1
VALUE1

But when I do

$ python -c "import os; print os.environ.get('KEY1')"
None
$

Why might this be the case?

Answer 1

You might not have exported the variable. You can think of export as a way of making a shell variable public and not private to the shell. Take a look at the export man page.

➜  ~ K=1    
➜  ~ echo $K 
1
➜  ~ python -c "import os; print os.environ.get('K')"   
None
➜  ~ export K=1
➜  ~ python -c "import os; print os.environ.get('K')"
1