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ConfigProvider

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API reference for ConfigProvider.

A source of configuration Node values, looked up by path.

load gives None for an absent path and fails with SourceError only when the source cannot be read; absence is what or_else falls back on. Build one with make, from_env, from_unknown, from_dot_env_contents or from_dir.

Functions

load

load(path) -> Effect[Node | None, SourceError]

The node at path after this provider's path transformations, or None when there is none.

ParameterTypeDescription
pathPathInput

Returns Effect[Node | None, SourceError]

@abstractmethod
def load(self, path: PathInput) -> Effect[Node | None, SourceError]:
    """The node at ``path`` after this provider's path transformations,
    or ``None`` when there is none."""

map_input

map_input(f) -> ConfigProvider

A provider that applies f to lookup paths after its existing transformations. or_else providers apply it to both operands.

ParameterTypeDescription
fCallable[[Path], PathInput]

Returns ConfigProvider

@abstractmethod
def map_input(self, f: Callable[[Path], PathInput]) -> ConfigProvider:
    """A provider that applies ``f`` to lookup paths after its existing
    transformations. ``or_else`` providers apply it to both operands."""

or_else

or_else(that) -> ConfigProvider

Look up in this provider, then in that when the path is absent here. A SourceError does not fall back, and found containers are not merged.

ParameterTypeDescription
thatConfigProvider

Returns ConfigProvider

def or_else(self, that: ConfigProvider) -> ConfigProvider:
    """Look up in this provider, then in ``that`` when the path is
    absent here. A ``SourceError`` does not fall back, and found
    containers are not merged."""
    return _OrElse(self, that)

nested

nested(prefix) -> ConfigProvider

Look every path up under prefix.

ParameterTypeDescription
prefixstr | PathInput

Returns ConfigProvider

def nested(self, prefix: str | PathInput) -> ConfigProvider:
    """Look every path up under ``prefix``."""
    head = (prefix,) if isinstance(prefix, str) else to_path(prefix)
    return self.map_input(lambda path: head + path)

constant_case

constant_case() -> ConfigProvider

Convert string segments to CONSTANT_CASE (Effect's configCase: "databaseHost" is "DATABASE_HOST", "api-v2" is "API_V2"); numeric segments are kept.

Returns ConfigProvider

def constant_case(self) -> ConfigProvider:
    """Convert string segments to CONSTANT_CASE (Effect's ``configCase``:
    ``"databaseHost"`` is ``"DATABASE_HOST"``, ``"api-v2"`` is
    ``"API_V2"``); numeric segments are kept."""
    return self.map_input(_constant_case)