quality-of-life improvements for python bindings

bindings/python/example_scripts/simple_book.py

@@ -11,15 +11,15 @@ from gnucash import Session
 uri = "xml:///tmp/simple_book.gnucash"
 
 print("uri:", uri)
-ses = Session(uri, is_new=True)
+with Session(uri, is_new=True) as ses:
     book = ses.get_book()
 
     #Call some methods that produce output to show that Book works
     book.get_root_account().SetDescription("hello, book")
     print("Book is saved:", not book.session_not_saved())
 
+    #As long as there's no exceptions, book is automatically saved
+    #when session ends.
     print("saving...")
-ses.save()
 
 print("Book is saved:", not book.session_not_saved())
-ses.end()

bindings/python/example_scripts/simple_session.py

@@ -19,18 +19,13 @@ except GnuCashBackendException as backend_exception:
 
 
 # create a new file, this requires a file type specification
-session = Session("xml://%s" % FILE_2, is_new=True)
-session.save()
-session.end()
-session.destroy()
+with Session("xml://%s" % FILE_2, is_new=True) as session:
+    book = session.book
+    root = book.get_root_account()
 
 # open the new file, try to open it a second time, detect the lock
-session = Session(FILE_2)
+with Session(FILE_2) as session:
     try:
         session_2 = Session(FILE_2)
     except GnuCashBackendException as backend_exception:
         assert( ERR_BACKEND_LOCKED in backend_exception.errors )
-session.end()
-session.destroy()
-
-    

bindings/python/example_scripts/simple_test.py

@@ -7,7 +7,7 @@ from gnucash import Session, Account, Transaction, Split, GncNumeric
 
 FILE_1 = "/tmp/example.gnucash"
 
-session = Session("xml://%s" % FILE_1, is_new=True)
+with Session("xml://%s" % FILE_1, is_new=True) as session:
 
     book = session.book
     root_acct = Account(book)
@@ -81,7 +81,3 @@ split4.SetValue(num2.neg())
 
     trans1.CommitEdit()
     trans2.CommitEdit()
-
-session.save()
-session.end()
-session.destroy()

bindings/python/gnucash_core.py

@@ -117,6 +117,15 @@ class Session(GnuCashCoreClass):
                 self.destroy()
                 raise
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        # Roll back changes on exception by not calling save. Only works for XMl backend.
+        if not exc_type:
+            self.save()
+        self.end()
+
     def raise_backend_errors(self, called_function="qof_session function"):
         """Raises a GnuCashBackendException if there are outstanding
         QOF_BACKEND errors.
@@ -434,6 +443,9 @@ class Transaction(GnuCashCoreClass):
         return self.do_lookup_create_oo_instance(
             gncInvoiceGetInvoiceFromTxn, Transaction )
 
+    def __eq__(self, other):
+        return self.Equal(other, True, False, False, False)
+
 def decorate_monetary_list_returning_function(orig_function):
     def new_function(self, *args):
         """decorate function that returns list of gnc_monetary to return tuples of GncCommodity and GncNumeric
@@ -461,6 +473,9 @@ class Split(GnuCashCoreClass):
     """
     _new_instance = 'xaccMallocSplit'
 
+    def __eq__(self, other):
+        return self.Equal(other, True, False, False)
+
 class Account(GnuCashCoreClass):
     """A GnuCash Account.
 

bindings/python/tests/test_split.py

@@ -57,6 +57,11 @@ class TestSplit( SplitSession ):
     def test_equal(self):
         COPY = self.split
         self.assertTrue( self.split.Equal(COPY, True, False, False) )
+        # test __eq__ implementation
+        TRANS = Transaction(self.book)
+        self.split.SetParent(TRANS)
+        self.assertTrue( self.split == TRANS.GetSplitList()[0] )
+        self.assertTrue( self.split != Split(self.book) )
 
 if __name__ == '__main__':
     main()

bindings/python/tests/test_transaction.py

@@ -44,6 +44,11 @@ class TestTransaction( TransactionSession ):
     def test_equal(self):
         TRANS = self.trans
         self.assertTrue( TRANS.Equal(self.trans, True, False, False, False) )
+        # test __eq__ implementation
+        SPLIT = Split(self.book)
+        SPLIT.SetParent(TRANS)
+        self.assertTrue( self.trans == SPLIT.GetParent() )
+        self.assertTrue( self.trans != Transaction(self.book) )
 
     def test_clone(self):
         domain = "gnc.engine"