Enable specifying the password in config.ini

oemof_pg/db.py

@@ -1,16 +1,31 @@
+from configparser import NoOptionError as option, NoSectionError as section
 from sqlalchemy import create_engine
 import keyring
 from . import config as cfg
 
 
 def connection():
+    pw = keyring.get_password(cfg.get("postGIS", "database"),
+                              cfg.get("postGIS", "username"))
+
+    if pw is None:
+      try: pw = cfg.get("postGIS", "pw")
+      except option:
+          print("Unable to find the database password in " +
+                "the oemof config or keyring." +
+                "\nExiting.")
+          exit(-1)
+      except section:
+          print("Unable to find the 'postGIS' section in oemof's config." +
+                "\nExiting.")
+          exit(-1)
+
     engine = create_engine(
         "postgresql+psycopg2://{user}:{passwd}@{host}:{port}/{db}".format(
             user=cfg.get("postGIS", "username"),
-            passwd=keyring.get_password(
-                cfg.get("postGIS", "database"),
-                cfg.get("postGIS", "username")),
+            passwd=pw,
             host=cfg.get("postGIS", "host"),
             db=cfg.get("postGIS", "database"),
             port=int(cfg.get("postGIS", "port"))))
+
     return engine.connect()