supressing exception when finding postgres version

Author: dantownsend

piccolo/engine/base.py

@@ -15,7 +15,6 @@ class Batch:
 class Engine(metaclass=ABCMeta):
     def __init__(self):
         self.check_version()
-        self.tables = []
 
     @property
     @abstractmethod

piccolo/engine/postgres.py

@@ -16,6 +16,7 @@
 from piccolo.query.base import Query
 from piccolo.querystring import QueryString
 from piccolo.utils.sync import run_sync
+from piccolo.utils.warnings import colored_warning
 
 
 @dataclass
@@ -220,12 +221,19 @@ def get_version(self) -> float:
                 self._run_in_new_connection("SHOW server_version"),
             )
 
-        response: t.Sequence[t.Dict] = future.result()
-
-        server_version = response[0]["server_version"]
-        major, minor, _ = server_version.split(".")
-        version = float(f"{major}.{minor}")
-        return version
+        try:
+            response: t.Sequence[t.Dict] = future.result()
+        except ConnectionRefusedError as exception:
+            # Suppressing the exception, otherwise importing piccolo_conf.py
+            # containing an engine will raise an ImportError.
+            colored_warning("Unable to connect to database")
+            print(exception)
+            return 0.0
+        else:
+            server_version = response[0]["server_version"]
+            major, minor, _ = server_version.split(".")
+            version = float(f"{major}.{minor}")
+            return version
 
     ###########################################################################