8

I am running Ubuntu on a local PC with the following linux distro/kernel:

$ lsb_release -a
>> ubuntu 16.04.3 LTS

$ uname -r
>> 4.10.0-33-generic

I have a python (3.5) script which calls environment variables via the os package.

For the sake of simplicity, let's use the following script, test_script.py:

import os

MY_VAR = os.environ['MY_VAR']
print(MY_VAR)

When I run this script from terminal:

$ python test_script.py
>>  File "test-script.py", line 3, in <module>
>>    MY_VAR = os.environ['MY_VAR']
>>  File "/home/USER/anaconda3/lib/python3.6/os.py", line 669, in __getitem__
>>    raise KeyError(key) from None
>> KeyError: 'MY_VAR'

ATTEMPT 1

Reference: [1][4]

$ MY_VAR=123
$ export MY_VAR
$ echo $MY_VAR
>> 123
$ python test_script.py
>> 123

Success! ... until I close terminal and reopen terminal. When I do that:

$ python test_script.py
>>  File "test-script.py", line 3, in <module>
>>    MY_VAR = os.environ['MY_VAR']
>>  File "/home/USER/anaconda3/lib/python3.6/os.py", line 669, in __getitem__
>>    raise KeyError(key) from None
>> KeyError: 'MY_VAR'

ATTEMPT 2

Reference: [2]

To the end of /home/USER/.profile, I add the following lines:

# my variable
MYVAR=123

Save. Confirm saved.

$ python test_script.py
>>  File "test-script.py", line 3, in <module>
>>    MY_VAR = os.environ['MY_VAR']
>>  File "/home/USER/anaconda3/lib/python3.6/os.py", line 669, in __getitem__
>>    raise KeyError(key) from None
>> KeyError: 'MY_VAR'

ATTEMPT 3

Reference: [2]

To the end of /etc/profile, I add the following lines:

# my variable
MYVAR=123

Save. Confirm saved.

$ python test_script.py
>>  File "test-script.py", line 3, in <module>
>>    MY_VAR = os.environ['MY_VAR']
>>  File "/home/USER/anaconda3/lib/python3.6/os.py", line 669, in __getitem__
>>    raise KeyError(key) from None
>> KeyError: 'MY_VAR'

ATTEMPT 4

Reference: [2]

Create myvar.sh in /etc/profile.d/

Add the following line:

MYVAR=123

Save. Confirm saved.

$ python test_script.py
>>  File "test-script.py", line 3, in <module>
>>    MY_VAR = os.environ['MY_VAR']
>>  File "/home/USER/anaconda3/lib/python3.6/os.py", line 669, in __getitem__
>>    raise KeyError(key) from None
>> KeyError: 'MY_VAR'

ATTEMPT 5

Reference: [2][3]

To the end of /etc/environment, I add the following line:

MYVAR=123

Save. Confirm saved.

$ python test_script.py
>>  File "test-script.py", line 3, in <module>
>>    MY_VAR = os.environ['MY_VAR']
>>  File "/home/USER/anaconda3/lib/python3.6/os.py", line 669, in __getitem__
>>    raise KeyError(key) from None
>> KeyError: 'MY_VAR'

Please help! I don't understand what I'm doing wrong here.

  1. How to set environment variables permanently for one user
  2. Permanent Environment Variable for all users
  3. How to permanently set environmental variables
  4. How do I set a user environment variable? (permanently, not session)
Craig van Tonder
  • 103
  • 4
xibalba1
  • 183

1 Answers1

13

You should use the approaches in attempt 3 or 4, but you need to export the variable; change

MYVAR=123

to

export MYVAR=123
Stephen Kitt
  • 434,908
  • Please, write the whole solution, it'll be more useful. – Fran Marzoa Aug 05 '18 at 14:20
  • This solution did NOT work for me on Ubuntu 18.04. I attempted to create MYVAR=123 even with the export keyword before it, both in /etc/profile and /etc/profile.d/myvar.sh however when I echo $MYVAR it is empty. – ipkpjersi Aug 29 '19 at 13:39
  • 1
    @ipkpjersi are you using bash? Are you starting it as a login shell? – Stephen Kitt Aug 29 '19 at 14:11
  • I tried with Bash and Zsh. Zsh is my login shell. – ipkpjersi Aug 29 '19 at 14:23
  • 1
    It doesn’t matter what your login shell is; what matters is whether you’re starting the shell as a login shell. That depends on how you’re starting it: are you starting it from a terminal emulator? If so, which one? – Stephen Kitt Aug 29 '19 at 14:32
  • I may have missed something but in 20.04, #4 only seems to work on the user that is used to login to the shell. #5 works in users that are switched to (interactive shell?) and without restart if you source /etc/environment Further reading: https://stackoverflow.com/a/1641505/2110294 – Craig van Tonder Mar 28 '22 at 23:02