Config Overlay

Configuration overlays start with defaults and then apply environment-specific values.

config_overlay.py

base = {
    "debug": "false",
    "region": "us",
    "workers": "2",
}

dev = {
    "debug": "true",
    "workers": "1",
}

prod = {
    "region": "eu",
    "workers": "4",
}

environment = 

config = base.copy()
if environment == "dev":
    config.update(dev)
else:
    config.update(prod)

parts = []
for key in sorted(config):
    parts.append(key + "=" + config[key])

print("config=" + ";".join(parts))

base = {
    "debug": "false",
    "region": "us",
    "workers": "2",
}

dev = {
    "debug": "true",
    "workers": "1",
}

prod = {
    "region": "eu",
    "workers": "4",
}

environment = 

config = base.copy()
if environment == "dev":
    config.update(dev)
else:
    config.update(prod)

parts = []
for key in sorted(config):
    parts.append(key + "=" + config[key])

print("config=" + ";".join(parts))

dictionary overlay Copying defaults before update keeps the base configuration unchanged.