[qa] test_framework: Properly print exceptions and assert empty dict

Github-Pull: #7951
Rebased-From: 5555528b47b7d33a5b963c076e6bb09ee25931b5 fada064f67302502f6b51d9d22927381c2707cbb

qa/rpc-tests/test_framework/mininode.py

@@ -93,7 +93,7 @@ def deser_uint256(f):
 
 
 def ser_uint256(u):
-    rs = ""
+    rs = b""
     for i in xrange(8):
         rs += struct.pack("<I", u & 0xFFFFFFFFL)
         u >>= 32
@@ -191,7 +191,7 @@ def deser_string_vector(f):
 
 
 def ser_string_vector(l):
-    r = ""
+    r = b""
     if len(l) < 253:
         r = struct.pack("B", len(l))
     elif len(l) < 0x10000:
@@ -624,7 +624,7 @@ class CAlert(object):
         self.vchSig = deser_string(f)
 
     def serialize(self):
-        r = ""
+        r = b""
         r += ser_string(self.vchMsg)
         r += ser_string(self.vchSig)
         return r
@@ -988,7 +988,7 @@ class msg_reject(object):
     def __init__(self):
         self.message = b""
         self.code = 0
-        self.reason = ""
+        self.reason = b""
         self.data = 0L
 
     def deserialize(self, f):

qa/rpc-tests/test_framework/test_framework.py

@@ -143,7 +143,7 @@ class BitcoinTestFramework(object):
             print("Assertion failed: "+ str(e))
             traceback.print_tb(sys.exc_info()[2])
         except Exception as e:
-            print("Unexpected exception caught during testing: "+str(e))
+            print("Unexpected exception caught during testing: " + repr(e))
             traceback.print_tb(sys.exc_info()[2])
 
         if not self.options.noshutdown:

qa/rpc-tests/test_framework/util.py

@@ -488,7 +488,7 @@ def assert_array_result(object_array, to_match, expected, should_not_find = Fals
         in object_array
         """
     if should_not_find == True:
-        expected = { }
+        assert_equal(expected, { })
     num_matched = 0
     for item in object_array:
         all_match = True