Function that reads environment variables from .env file and adds them to the os.environment dictionary.

read_env.py

# manage.py in Django project
import re

def read_env():
    """
    Pulled from Honcho code with minor updates, reads local default
    environment variables from a .env file located in the project root
    directory.
    """
    try:
        with open('.env') as f:
            content = f.read()
    except IOError:
        content = ''

    for line in content.splitlines():
        m1 = re.match(r'\A([A-Za-z_0-9]+)=(.*)\Z', line)
        if m1:
            key, val = m1.group(1), m1.group(2)
            m2 = re.match(r"\A'(.*)'\Z", val)
            if m2:
                val = m2.group(1)
            m3 = re.match(r'\A"(.*)"\Z', val)
            if m3:
                val = re.sub(r'\\(.)', r'\1', m3.group(1))
            os.environ.setdefault(key, val)

# within __name__ == "main"
read_env()