pydantic-settings 0.1.0a1

Hipster-orgazmic tool to mange application settings

Pydantic Settings

Library which extends pydantic functionality in scope of application settings.

Pydantic already have settings implementation, e.g. pydantic.BaseSettings, but from my point it's missing some useful features, listed below.

Features

1. Point exact location of a failed field in the text
2. Override file values by environment variables, even if a field is nested

Allow to override values for nested fields if they are represented as pydantic model, dataclass or attrs dataclass. Here is example:

@dataclass
class Nested:
    foo: int

class Settings(SettingsModel):
    nested: Nested


try:
    Settings.from_env({'APP_NESTED_FOO': 'NOT AN INT'})
except ValidationError as e:
    assert e.raw_errors[0].env_loc = 'APP_NESTED_FOO'

3. Shows right environment variable name for failed field

try:
    Settings.from_env({'APP_nested_FOO': 'NOT AN INT'})
except ValidationError as e:
    assert e.raw_errors[0].env_loc = 'APP_nested_FOO'

4. Extracts field documentation from Sphinx style attributes documentation by processing AST tree of class definition

class Foo(SettingsModel):
    class Config:
        extract_docs = True

    bar: str
    """here is docs"""

    #: this style is't supported, but probably will be added in future
    baz: int

assert Foo.__field__['bar'].schema.description == 'here is docs'
assert Foo.__field__['baz'].schema.description == ''  # :(

5. Render documentation examples with commentaries taken from fields description

class Settings(SettingsModel):
    host: str = 'localhost'
    """
    Self domain name
    """

    auth_secret: SecretStr
    """
    Secret key used to encrypt user tokens with HMAC-SHA256
    """


EXAMPLE_SETTINGS = Settings(
    host='host.name',
    auth_secret='5O5qOWiM5qnvUwvQtP1_bUTonSIn7I7C66eqVGL2it0=',
)

assert dumper(EXAMPLE_SETTINGS, 'yaml') == """
# Self domain name
host: host.name

# Secret key used to encrypt user tokens with HMAC-SHA256
auth_secret: 5O5qOWiM5qnvUwvQtP1_bUTonSIn7I7C66eqVGL2it0
"""

Development status

1. partially, only json and yaml supported for now
2. doesn't supports overriding inside list, case-sensitive implementation
3. done
4. done (attr classes not supported for now)
5. not started