Feature request: Allow for mixed case keys when configuring from environment variables #94
Description
Current Situation
A configuration setup for myproject, that contains uppercase letters like
ABC: "an uppercase value"
abc: "a lowercase value"currently cannot be configured via environment variables, as the keys encoded into the environment variable names are always converted to lowercase.
Requested Improvement
Allow to configure myproject for above configuration structure via
export myproject_ABC="another uppercase value"
export myproject_abc="another lowercase value"Implementation
Assuming that the (undocumented) env_prefix parameter of the class Config is rarely used in client code I suggest, that if it is explicitly set to a value, that contains lowercase letters:
from donfig import Config
config = Config('myproject', env_prefix='myproject')the conversion of found environment variables to lowercase is skipped:
...
if any(char.islower() for char in prefix):
varname = name[prefix_len:].replace("__", ".")
else:
varname = name[prefix_len:].lower().replace("__", ".")
...Analysis
The mentioned approach is not 100% backwards compatible: If any client code uses the following:
from donfig import Config
config = Config('myproject', env_prefix='myProject')to be able to use mixed case environment Variables
export myProject_ABC="a value"to read in a configuration equivalent to
abc: "a value"the change would break this.
Alternative
Add a boolean env_case_sensitive keyword parameter to the class donfig.Config and use it:
class Config:
def __init__(
self,
name: str,
defaults: list[Mapping[str, Any]] | None = None,
paths: list[str] | None = None,
env: Mapping[str, str] | None = None,
env_var: str | None = None,
root_env_var: str | None = None,
env_prefix: str | None = None,
deprecations: Mapping[str, str | None] | None = None,
env_case_sensitive: bool = False,
):