DotEnv ValueError when env variable name is shorter than env_prefix

[jvllmr]

Example:

class DramatiqSettings(BaseSettings):
    broker_url: RedisDsn

    model_config = SettingsConfigDict(
        env_file=".env", env_prefix="plato_worker_", extra="ignore"  # type: ignore
    )

I also have another settings class that holds my general application settings.

When processing my PLATO_DEBUG env var, the following line fails:

pydantic-settings/pydantic_settings/sources.py

Line 583 in 373af71

first_key, *_ = env_name_without_prefix.split(self.env_nested_delimiter)

ValueError: not enough values to unpack (expected at least 1, got 0)

It's because PLATO_DEBUG is shorter than the env_prefix for my DramatiqSettings class.

Possible Solution:
Check if the env var name actually starts with the env prefix before stripping the name.

Selected Assignee: @samuelcolvin

[jvllmr]

I realised that this also happens when extras are forbidden

[hramezani]

Thanks @jvllmr for reporting this 🙏

Would you mind opening a PR for fixing this? otherwise, I will fix it.