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)
-book = ses.get_book()
+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())
+    #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())
 
-print("saving...")
-ses.save()
+    #As long as there's no exceptions, book is automatically saved
+    #when session ends.
+    print("saving...")
 
 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)
-try:
+with Session(FILE_2) as session:
+    try:
         session_2 = Session(FILE_2)
-except GnuCashBackendException as backend_exception:
+    except GnuCashBackendException as backend_exception:
         assert( ERR_BACKEND_LOCKED in backend_exception.errors )
-session.end()
-session.destroy()
-
-    

bindings/python/example_scripts/simple_test.py

@@ -7,81 +7,77 @@ 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)
-expenses_acct = Account(book)
-savings_acct = Account(book)
-opening_acct = Account(book)
-trans1 = Transaction(book)
-trans1.BeginEdit()
-trans2 = Transaction(book)
-trans2.BeginEdit()
+    book = session.book
+    root_acct = Account(book)
+    expenses_acct = Account(book)
+    savings_acct = Account(book)
+    opening_acct = Account(book)
+    trans1 = Transaction(book)
+    trans1.BeginEdit()
+    trans2 = Transaction(book)
+    trans2.BeginEdit()
 
-split1 = Split(book)
-split3 = Split(book)
-comm_table = book.get_table()
-cad = comm_table.lookup("CURRENCY", "CAD")
+    split1 = Split(book)
+    split3 = Split(book)
+    comm_table = book.get_table()
+    cad = comm_table.lookup("CURRENCY", "CAD")
 
-num1 = GncNumeric(4, 1)
-num2 = GncNumeric(100, 1)
+    num1 = GncNumeric(4, 1)
+    num2 = GncNumeric(100, 1)
 
-#Set new root account
-book.set_root_account(root_acct)
+    #Set new root account
+    book.set_root_account(root_acct)
 
-#Set up root account and add sub-accounts
-root_acct.SetName("Root")
-root_acct.SetType(13) #ACCT_TYPE_ROOT = 13
-root_acct.append_child(expenses_acct)
-root_acct.append_child(savings_acct)
-root_acct.append_child(opening_acct)
+    #Set up root account and add sub-accounts
+    root_acct.SetName("Root")
+    root_acct.SetType(13) #ACCT_TYPE_ROOT = 13
+    root_acct.append_child(expenses_acct)
+    root_acct.append_child(savings_acct)
+    root_acct.append_child(opening_acct)
 
-#Set up Expenses account
-expenses_acct.SetCommodity(cad)
-expenses_acct.SetName("Expenses")
-expenses_acct.SetType(9) #ACCT_TYPE_EXPENSE = 9
+    #Set up Expenses account
+    expenses_acct.SetCommodity(cad)
+    expenses_acct.SetName("Expenses")
+    expenses_acct.SetType(9) #ACCT_TYPE_EXPENSE = 9
 
-#Set up Savings account
-savings_acct.SetCommodity(cad)
-savings_acct.SetName("Savings")
-savings_acct.SetType(0) #ACCT_TYPE_BANK = 0
+    #Set up Savings account
+    savings_acct.SetCommodity(cad)
+    savings_acct.SetName("Savings")
+    savings_acct.SetType(0) #ACCT_TYPE_BANK = 0
 
-#Set up Opening Balance account
-opening_acct.SetCommodity(cad)
-opening_acct.SetName("Opening Balance")
-opening_acct.SetType(10) #ACCT_TYPE_EQUITY = 10
+    #Set up Opening Balance account
+    opening_acct.SetCommodity(cad)
+    opening_acct.SetName("Opening Balance")
+    opening_acct.SetType(10) #ACCT_TYPE_EQUITY = 10
 
-split1.SetValue(num1)
-split1.SetAccount(expenses_acct)
-split1.SetParent(trans1)
+    split1.SetValue(num1)
+    split1.SetAccount(expenses_acct)
+    split1.SetParent(trans1)
 
-split3.SetValue(num2)
-split3.SetAccount(savings_acct)
-split3.SetParent(trans2)
+    split3.SetValue(num2)
+    split3.SetAccount(savings_acct)
+    split3.SetParent(trans2)
 
-trans1.SetCurrency(cad)
-trans1.SetDate(14, 3, 2006)
-trans1.SetDescription("Groceries")
+    trans1.SetCurrency(cad)
+    trans1.SetDate(14, 3, 2006)
+    trans1.SetDescription("Groceries")
 
-trans2.SetCurrency(cad)
-trans2.SetDate(7, 11, 1995)
-trans2.SetDescription("Opening Savings Balance")
+    trans2.SetCurrency(cad)
+    trans2.SetDate(7, 11, 1995)
+    trans2.SetDescription("Opening Savings Balance")
 
-split2 = Split(book)
-split2.SetAccount(savings_acct)
-split2.SetParent(trans1)
-split2.SetValue(num1.neg())
+    split2 = Split(book)
+    split2.SetAccount(savings_acct)
+    split2.SetParent(trans1)
+    split2.SetValue(num1.neg())
 
-split4 = Split(book)
-split4.SetAccount(opening_acct)
-split4.SetParent(trans2)
-split4.SetValue(num2.neg())
+    split4 = Split(book)
+    split4.SetAccount(opening_acct)
+    split4.SetParent(trans2)
+    split4.SetValue(num2.neg())
 
 
-trans1.CommitEdit()
-trans2.CommitEdit()
-
-session.save()
-session.end()
-session.destroy()
+    trans1.CommitEdit()
+    trans2.CommitEdit()

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"