Django manage.py file that loads environment variables from a .env file per Honcho/Foreman

LICENSE

Copyright the authors of Honcho and/or Ben Lopatin

Licensed for reuse, modification, and distribution under the terms of the MIT license

manage.py

#!/usr/bin/env python
import os
import sys
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)


if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project_name.settings")

    from django.core.management import execute_from_command_line

    read_env()
    execute_from_command_line(sys.argv)

original.py

#!/usr/bin/env python
import os
import sys

if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project_name.settings")

    from django.core.management import execute_from_command_line

    execute_from_command_line(sys.argv)

thank you!

This helped me a lot. Thanks! What license is this gist under?

This helped me a lot. Thanks! What license is this gist under?

Just added a LICENSE file with an MIT license. Have at it.

Thanks! I have two questions.

Why do you remove a backslash character?
I'm not an expert with env variables and don't know of any case where there would be a backslash.

            m3 = re.match(r'\A"(.*)"\Z', val)
            if m3:
                val = re.sub(r'\\(.)', r'\1', m3.group(1))

Also as someone mentioned above,

Why not just return instead of setting content = '' ?

I think it's worth noting (for people who won't read the blog post) that if you want to use Booleans in the .env file then you need to parse the string yourself. In the blog they use this function:

def env_var(key, default=None):
    """Retrieves env vars and makes Python boolean replacements"""
    val = os.environ.get(key, default)
    if val == 'True':
        val = True
    elif val == 'False':
        val = False
    return val

Hey! It not work, when you need use custom .env file in django app. It searches from .env file in django root settings directory.

Thank you very much!!!!
I change:
with open('.env') as f:
for
with open('path/to/.env') as f:
and works fantastic

Very useful, thanks.

I use honcho in some of my deployment scripts, so in that case I don't want the local .env file mucking things up.

I added a check before the "try" block that simply returns from read_env() if one of my environment variables is already set.

# Don't do anything if the environment is already loaded
# If YOUR_VARIABLE is defined then exit
if os.environ.get("YOUR_VARIABLE") is not None:
    print("Environment already loaded.  Ignoring .env")
    return

try:
    with open("../.env") as f:
        content = f.read()
except IOError:
    return`

Obviously replace YOUR_VARIABLE with, well, your variable!