Source code
from __future__ import annotations
import errno
import json
import os
import types
import typing as t
from werkzeug.utils import import_string
class Config(dict):
def __init__(
self,
root_path: str | os.PathLike[str],
defaults: dict[str, t.Any] | None = None,
) -> None:
super().__init__(defaults or {})
self.root_path = root_path
def from_envvar(self, variable_name: str, silent: bool = False) -> bool:
rv = os.environ.get(variable_name)
if not rv:
if silent:
return False
raise RuntimeError(
f"The environment variable {variable_name!r} is not set"
" and as such configuration could not be loaded. Set"
" this variable and make it point to a configuration"
" file"
)
return self.from_pyfile(rv, silent=silent)
def from_prefixed_env(
self, prefix: str = "FLASK", *, loads: t.Callable[[str], t.Any] = json.loads
) -> bool:
prefix = f"{prefix}_"
for key in sorted(os.environ):
if not key.startswith(prefix):
continue
value = os.environ[key]
key = key.removeprefix(prefix)
try:
value = loads(value)
except Exception:
pass
if "__" not in key:
self[key] = value
continue
current = self
*parts, tail = key.split("__")
for part in parts:
if part not in current:
current[part] = {}
current = current[part]
current[tail] = value
return True
def from_pyfile(
self, filename: str | os.PathLike[str], silent: bool = False
) -> bool:
filename = os.path.join(self.root_path, filename)
d = types.ModuleType("config")
d.__file__ = filename
try:
with open(filename, mode="rb") as config_file:
exec(compile(config_file.read(), filename, "exec"), d.__dict__)
except OSError as e:
if silent and e.errno in (errno.ENOENT, errno.EISDIR, errno.ENOTDIR):
return False
e.strerror = f"Unable to load configuration file ({e.strerror})"
raise
self.from_object(d)
return True
def from_object(self, obj: object | str) -> None:
if isinstance(obj, str):
obj = import_string(obj)
for key in dir(obj):
if key.isupper():
self[key] = getattr(obj, key)
def from_file(
self,
filename: str | os.PathLike[str],
load: t.Callable[[t.IO[t.Any]], t.Mapping[str, t.Any]],
silent: bool = False,
text: bool = True,
) -> bool:
filename = os.path.join(self.root_path, filename)
try:
with open(filename, "r" if text else "rb") as f:
obj = load(f)
except OSError as e:
if silent and e.errno in (errno.ENOENT, errno.EISDIR):
return False
e.strerror = f"Unable to load configuration file ({e.strerror})"
raise
return self.from_mapping(obj)
def from_mapping(
self, mapping: t.Mapping[str, t.Any] | None = None, **kwargs: t.Any
) -> bool:
mappings: dict[str, t.Any] = {}
if mapping is not None:
mappings.update(mapping)
mappings.update(kwargs)
for key, value in mappings.items():
if key.isupper():
self[key] = value
return True
def get_namespace(
self, namespace: str, lowercase: bool = True, trim_namespace: bool = True
) -> dict[str, t.Any]:
rv = {}
for k, v in self.items():
if not k.startswith(namespace):
continue
if trim_namespace:
key = k[len(namespace) :]
else:
key = k
if lowercase:
key = key.lower()
rv[key] = v
return rv
def __repr__(self) -> str:
return f"<{type(self).__name__} {dict.__repr__(self)}>"