Reduce number of required API calls

grapheneapi/api.py

@@ -39,15 +39,19 @@ def __init__(self, urls, user=None, password=None, connect=True, **kwargs):
         # Let's also be able to deal with infinite connection
         self.urls = cycle(urls)
         self._cnt_retries = 0
+        self._network = None
 
         # Connect!
         if connect:
             self.connect()
+            self._network = self.get_network()
 
     # Get chain parameters
     @property
     def chain_params(self):
-        return self.get_network()
+        if self._network is None:
+            self._network = self.get_network()
+        return self._network
 
     def get_network(self):
         return self.get_chain_properties()

graphenecommon/chain.py

@@ -228,7 +228,7 @@ def finalizeOp(self, ops, account, permission, **kwargs):
         elif self.bundle:
             # In case we want to add more ops to the tx (bundle)
             self.txbuffer.appendSigner(account, permission)
-            return self.txbuffer.json()
+            return self.txbuffer
         else:
             # default behavior: sign + broadcast
             self.txbuffer.appendSigner(account, permission)

graphenecommon/transactionbuilder.py

@@ -36,7 +36,7 @@ def __init__(
         proposal_review=None,
         parent=None,
         *args,
-        **kwargs
+        **kwargs,
     ):
         self.define_classes()
         assert self.operation_class