Environment variable not available in python

Question

I have a pretty interesting problem regarding environment variables, and googling around didn't show me any meaningful results:

$ echo $BUCKET && python -c "import os; print os.environ['BUCKET']" mule-uploader-demo Traceback (most recent call last): File "<string>", line 1, in <module> File "/usr/lib/python2.7/UserDict.py", line 23, in __getitem__ raise KeyError(key) KeyError: 'BUCKET' 

So I have an environment variable that is available in bash but not inside python. How can this happen and how do I fix it? Here are some additional details:

• The environment variable is set through a source envvars.sh command
• The envvars.sh file contains only lines that look like this: KEY=value
• I've reproduced this in both bash and zsh
• If I do an export BUCKET=$BUCKET, it works

Answer 1

This has to do with the variable scope in bash. export makes your variable available to subprocesses, see for example:

→ export BUCKET=foo → env | grep BUCKET 80:BUCKET=foo → PAIL=bar → env | grep PAIL # no output → python -c "import os; print os.environ['BUCKET']" foo → python -c "import os; print os.environ['PAIL']" Traceback (most recent call last): File "<string>", line 1, in <module> File "...", line 23, in __getitem__ raise KeyError(key) KeyError: 'PAIL' → CAN=baz python -c "import os; print os.environ['CAN']" baz 

so in a child process PAIL is a fail.