Bug #675201 - slight bugfix to prior enchancement post for example

scripts
Patch by Jamie Campbell

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@22231 57a11ea4-9604-0410-9ed3-97b8803252fd

src/optional/python-bindings/example_scripts/account_analysis.py

@@ -268,7 +268,7 @@ def main():
         # no save needed, we're just reading..
         gnucash_session.end()
     except:
-        if not gnucash_session == None:
+        if "gnucash_session" in locals():
             gnucash_session.end()
 
         raise

src/optional/python-bindings/example_scripts/new_book_with_opening_balances.py

@@ -343,10 +343,10 @@ def main():
         new_book_session.end()
         original_book_session.end()
     except:
-        if not original_book_session == None:
+        if "original_book_session" in locals():
             original_book_session.end()
  
-        if not new_book_session == None:
+        if "new_book_session" in locals():
             new_book_session.end()
 
         raise

src/optional/python-bindings/example_scripts/simple_business_create.py

@@ -69,9 +69,8 @@ if len(argv) < 2:
     exit()
     
 
-s = Session(argv[1], is_new=True)
-
 try:
+    s = Session(argv[1], is_new=True)
 
     book = s.book
     root = book.get_root_account()
@@ -185,6 +184,6 @@ try:
 
     s.end()
 except:
-    if not s == None:
+    if "s" in locals():
         s.end()
     raise

src/optional/python-bindings/example_scripts/test_imbalance_transaction.py

@@ -48,9 +48,10 @@ if len(argv) < 2:
     print "gnucash-env python test_imbalance_transaction.py '/home/username/test.gnucash'"
     exit()
 
-session = Session(argv[1])
 
 try:
+    session = Session(argv[1])
+
     book = session.book
 
     root = book.get_root_account()
@@ -98,6 +99,6 @@ try:
     session.end()
     session.destroy()
 except:
-    if not session == None:
+    if "session" in locals():
         session.end()
     raise