envcontext

Context manager to update environment variables with preservation

• envcontext on PyPI
• envcontext on PyPI Test

Installation

pip install envcontext

Usage

Ex. 1: Update environment variables in current process

from os import environ, getenv
from envcontext import EnvironmentContext as EnvContext

environ["TEST_VAR1"] = "original"

with EnvContext(TEST_VAR1="updated", TEST_VAR2="added"):
    print(environ["TEST_VAR1"])  # Prints "updated".
    print(environ["TEST_VAR2"])  # Prints "added".

print(getenv("TEST_VAR1"))  # Prints "original".
print(getenv("TEST_VAR2"))  # Should print "None".

Ex. 2: Update environment variables in child process

from subprocess import check_output
from envcontext import EnvironmentContext as EnvContext

with EnvContext(PGPASSWORD="very-secret-password"):
    check_output(["psql", "..."])  # psql process can manipulate PGPASSWORD.

Note: Ex. 2 is not working on Python 2.x because subprocess module bundled in Python 2.x doesn't propagate environment variables from current to child process.