Config

Works exactly like a dict but provides ways to fill it from files or special dictionaries. There are two common patterns to populate the config.

Attributes

Attribute	Type	Description
root_path	`str	os.PathLike[str]`

---

Constructor

Signature

def Config(
    root_path: str | os.PathLike[str],
    defaults: dict[str, t.Any]| None = None
) - > None

Parameters

Name	Type	Description
root_path	`str	os.PathLike[str]`
defaults	`dict[str, t.Any]	None` = None

---

Methods

---

from_envvar()

@classmethod
def from_envvar(
    variable_name: str,
    silent: bool = False
) - > bool

Loads a configuration from an environment variable pointing to a configuration file. This is basically just a shortcut with nicer error messages for this line of code: app.config.from_pyfile(os.environ['YOURAPPLICATION_SETTINGS'])

Parameters

Name	Type	Description
variable_name	str	The name of the environment variable that contains the path to the configuration file
silent	bool = False	Whether to suppress errors and return False if the environment variable is not set or the file is missing

Returns

Type	Description
bool	True if the file was loaded successfully.

---

from_prefixed_env()

@classmethod
def from_prefixed_env(
    prefix: str = FLASK,
    loads: t.Callable[[str], t.Any] = json.loads
) - > bool

Load any environment variables that start with FLASK_, dropping the prefix from the env key for the config key. Values are passed through a loading function to attempt to convert them to more specific types than strings.

Parameters

Name	Type	Description
prefix	str = FLASK	The prefix used to filter environment variables, which will be stripped from the resulting config keys
loads	t.Callable[[str], t.Any] = json.loads	A function used to deserialize the environment variable string value into a Python object

Returns

Type	Description
bool	Always returns True after processing matching environment variables

---

from_pyfile()

@classmethod
def from_pyfile(
    filename: str | os.PathLike[str],
    silent: bool = False
) - > bool

Updates the values in the config from a Python file. This function behaves as if the file was imported as module with the from_object function.

Parameters

Name	Type	Description
filename	`str	os.PathLike[str]`
silent	bool = False	Whether to suppress OSError exceptions if the file does not exist

Returns

Type	Description
bool	True if the file was loaded successfully.

---

from_object()

@classmethod
def from_object(
    obj: object | str
)

Updates the values from the given object. An object can be of one of the following two types: a string (imported as a module) or an actual object reference.

Parameters

Name	Type	Description
obj	`object	str`

---

from_file()

@classmethod
def from_file(
    filename: str | os.PathLike[str],
    load: t.Callable[[t.IO[t.Any]], t.Mapping[str, t.Any]],
    silent: bool = False,
    text: bool = True
) - > bool

Update the values in the config from a file that is loaded using the load parameter. The loaded data is passed to the from_mapping method.

Parameters

Name	Type	Description
filename	`str	os.PathLike[str]`
load	t.Callable[[t.IO[t.Any]], t.Mapping[str, t.Any]]	A callable that accepts a file handle and returns a dictionary-like mapping of configuration values
silent	bool = False	Whether to ignore errors if the file is missing from the filesystem
text	bool = True	Whether to open the file in text mode ('r') or binary mode ('rb')

Returns

Type	Description
bool	True if the file was loaded successfully.

---

from_mapping()

@classmethod
def from_mapping(
    mapping: t.Mapping[str, t.Any]| None = None,
    kwargs: t.Any
) - > bool

Updates the config like update ignoring items with non-upper keys.

Parameters

Name	Type	Description
mapping	`t.Mapping[str, t.Any]	None` = None
kwargs	t.Any	Arbitrary keyword arguments to be added to the configuration

Returns

Type	Description
bool	Always returns True.

---

get_namespace()

@classmethod
def get_namespace(
    namespace: str,
    lowercase: bool = True,
    trim_namespace: bool = True
) - > dict[str, t.Any]

Returns a dictionary containing a subset of configuration options that match the specified namespace/prefix.

Parameters

Name	Type	Description
namespace	str	The prefix string used to filter configuration keys
lowercase	bool = True	Whether to convert the resulting dictionary keys to lowercase
trim_namespace	bool = True	Whether to remove the namespace prefix from the resulting dictionary keys

Returns

Type	Description
dict[str, t.Any]	A dictionary containing the filtered configuration keys, optionally transformed

---