How to pass environment variables to pytest

Question

Before I start executing the tests in my Python project, I read some environment variables and set some variables with these values read. My tests will run on the desired environment based on these values read.

For eg: Let's say the environment variables are called ENV_NAME and ENV_NUMBER

Now, I would like to run the tests using py.test.

If I hard code these environment variables, for eg: ENV_NAME = 'staging', ENV_NUMBER = '5' in my code and then run the tests by executing the py.test command at the root of the project directory, all the tests run successfully.

But, I don't want to hardcode these values. Is there a way, I can send these environment variables as command line arguments for py.test?

I was thinking more in the lines of

py.test -ENV_NAME='staging' -ENV_NUMBER='5'.

But, this is not working.

Answer 1

Another alternative is to use the pytest-env plugin. It can be configured like so:

[pytest]
env = 
    HOME=~/tmp
    D:RUN_ENV=test

the D: prefix allows setting a default value, and not override existing variables passed to py.test.

Note: you can explicitly run pytest with a custom config, if you only sometimes need to run a specialized environment set up:

pytest -c custom_pytest.ini

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If you use PyCharm vs pytest-dotenv, this may be helpful