Connection: process pgsql connection param

omnipath_metabo/schema/_connection.py

@@ -1,4 +1,35 @@
+
+import os
+import yaml
+from contextlib import closing
+
 from sqlalchemy import create_engine
 
 class Connection:
-    def __init__(self, config_param, **kwargs ):
+    def __init__(
+            self,
+            param: str | dict | None = None,
+            **kwargs
+        ):
+
+        self._param = param or kwargs
+        self._parse_param()
+
+
+    def parse_param(self) -> None:
+
+        self._from_file()
+
+
+    def _from_file(self) -> None:
+
+        if isinstance(self._param, str) and os.path.exists(self._param):
+
+            self._param = yaml.load(
+                closing(open(self._param, 'r')),
+                Loader = yaml.FullLoader,
+            )
+
+    def _uri(self) -> str:
+
+        return f'postgresql://'