From e4169e84981a5f0cdc3c1c4ed9e9d5230f050f9e 2015-08-16 19:30:00
From: Lance Edgar <ledgar@sacfoodcoop.com>
Date: 2015-08-16 19:30:00
Subject: [PATCH] Add custom errors for when SA / Python for Windows Extensions not installed.

---

diff --git a/rattail/exceptions.py b/rattail/exceptions.py
index ab045316b57e58fa65c623ba1158206fe9a59710..63c95be1149c298efae5faf4508a38b2e245867c 100644
--- a/rattail/exceptions.py
+++ b/rattail/exceptions.py
@@ -41,6 +41,32 @@ class ConfigurationError(RattailError):
     """
 
 
+class SQLAlchemyNotInstalled(RattailError):
+    """
+    Error raised when an operation is requested which requires SQLAlchemy
+    (and/or related libraries) to be installed, but they are not available.
+    """
+    def __init__(self, error):
+        self.error = error
+
+    def __unicode__(self):
+        return ("Hm, looks like SQLAlchemy may not be installed?  "
+                "(Perhaps you should do: 'pip install rattail[db]'?)  "
+                "Original error was: {0}".format(self.error))
+
+
+class WindowsExtensionsNotInstalled(RattailError):
+    """
+    Error raised when an operation is requested which requires the "Python for
+    Windows Extensions" to be instealled, but it is not available.
+    """
+
+    def __unicode__(self):
+        return ("Cannot proceed because Python for Windows Extensions is not installed.  Please see "
+                "https://rattailproject.org/moin/Installation/Windows/Python#Python_for_Windows_Extensions "
+                "for more info.")
+
+
 class SenderNotFound(ConfigurationError):
 
     def __init__(self, key):