Refactor and reformat

great_ai/src/great_ai/utilities/config_file/config_file.py

@@ -1,52 +1,87 @@
-from pathlib import Path
 import os
-from typing import Dict, Union
+from pathlib import Path
+from typing import Dict, Iterable, Tuple, Union
 
 from ..logger import get_logger
 from .parse_error import ParseError
 from .pattern import pattern
 
-ENVIRONMENT_VARIABLE_KEY_PREFIX = 'ENV'
+ENVIRONMENT_VARIABLE_KEY_PREFIX = "ENV"
+
+logger = get_logger("ConfigFile")
 
-logger = get_logger('ConfigFile')
 
 class ConfigFile:
-    def __init__(self, path: Union[Path, str], ignore_missing_environment_variables:bool=False) -> None:
+    def __init__(
+        self, path: Union[Path, str], ignore_missing_environment_variables: bool = False
+    ) -> None:
         if not isinstance(path, Path):
             path = Path(path)
+
+        if not path.exists():
+            raise FileNotFoundError(path.absolute())
+
         self._path = path
-        self._ignore_missing_environment_variables = ignore_missing_environment_variables
+        self._ignore_missing_environment_variables = (
+            ignore_missing_environment_variables
+        )
         self._key_values: Dict[str, str] = {}
 
         self._parse()
 
     def _parse(self):
-        with open(self._path, encoding='utf-8') as f:
+        with open(self._path, encoding="utf-8") as f:
             lines: str = f.read()
 
         matches = pattern.findall(lines)
         for key, *values in matches:
             if key in self._key_values:
-                raise KeyError(f'Key `{key}` has been already defined and its value is `{value}`')
+                raise KeyError(
+                    f"Key `{key}` has been already defined and its value is `{self._key_values[key]}`"
+                )
 
             try:
                 value = next(v for v in values if v)
             except StopIteration:
-                raise ParseError(f'Cannot parse config file ({self._path.absolute()}), error at key `{key}`')
+                raise ParseError(
+                    f"Cannot parse config file ({self._path.absolute()}), error at key `{key}`"
+                )
 
-            if value.startswith(f'{ENVIRONMENT_VARIABLE_KEY_PREFIX}:'):
-                _, value = value.split(':')
+            if value.startswith(f"{ENVIRONMENT_VARIABLE_KEY_PREFIX}:"):
+                _, value = value.split(":")
                 if value not in os.environ:
                     issue = f'The value of `{key}` contains the "{ENVIRONMENT_VARIABLE_KEY_PREFIX}` prefix but `{value}` is not defined as an environment variable'
                     if self._ignore_missing_environment_variables:
-                        logger.warning(f'{issue}, defaulting to `None`')
+                        logger.warning(f"{issue}, defaulting to `None`")
                     else:
                         raise KeyError(issue)
                 value = os.environ[value]
-            
+
             self._key_values[key] = value
 
     def __getattr__(self, key: str) -> str:
         if key in self._key_values:
             return self._key_values[key]
-        raise KeyError(f'Key `{key}` is not found in configuration file ({self._path.absolute()})')
+        raise KeyError(
+            f"Key `{key}` is not found in configuration file ({self._path.absolute()})"
+        )
+
+    __getitem__ = __getattr__
+
+    def __iter__(self) -> Iterable[Tuple[str, str]]:
+        return iter(self._key_values)
+
+    def __len__(self) -> int:
+        return len(self._key_values)
+
+    def keys(self):
+        return self._key_values.keys()
+
+    def values(self):
+        return self._key_values.values()
+
+    def items(self):
+        return self._key_values.items()
+
+    def __repr__(self):
+        return f"{type(self).__name__}(\n  path={self._path},\n  ignore_missing_environment_variables={self._ignore_missing_environment_variables}\n) {{{self._key_values}}}"