Improve contract Python testcase testing

Catch expected exceptions only - fix bug in test

Examples/test-suite/python/contract_runme.py

@@ -2,16 +2,16 @@ import contract
 
 contract.test_preassert(1, 2)
 try:
-    contract.test_preassert(-1)
+    contract.test_preassert(-1, 3)
     print "Failed! Preassertions are broken"
-except:
+except RuntimeError:
     pass
 
 contract.test_postassert(3)
 try:
     contract.test_postassert(-3)
     print "Failed! Postassertions are broken"
-except:
+except RuntimeError:
     pass
 
 contract.test_prepost(2, 3)
@@ -19,14 +19,14 @@ contract.test_prepost(5, -4)
 try:
     contract.test_prepost(-3, 4)
     print "Failed! Preassertions are broken"
-except:
+except RuntimeError:
     pass
 
 try:
     contract.test_prepost(4, -10)
     print "Failed! Postassertions are broken"
 
-except:
+except RuntimeError:
     pass
 
 f = contract.Foo()
@@ -34,14 +34,14 @@ f.test_preassert(4, 5)
 try:
     f.test_preassert(-2, 3)
     print "Failed! Method preassertion."
-except:
+except RuntimeError:
     pass
 
 f.test_postassert(4)
 try:
     f.test_postassert(-4)
     print "Failed! Method postassertion"
-except:
+except RuntimeError:
     pass
 
 f.test_prepost(3, 4)
@@ -49,33 +49,33 @@ f.test_prepost(4, -3)
 try:
     f.test_prepost(-4, 2)
     print "Failed! Method preassertion."
-except:
+except RuntimeError:
     pass
 
 try:
     f.test_prepost(4, -10)
     print "Failed! Method postassertion."
-except:
+except RuntimeError:
     pass
 
 contract.Foo_stest_prepost(4, 0)
 try:
     contract.Foo_stest_prepost(-4, 2)
     print "Failed! Static method preassertion"
-except:
+except RuntimeError:
     pass
 
 try:
     contract.Foo_stest_prepost(4, -10)
     print "Failed! Static method posteassertion"
-except:
+except RuntimeError:
     pass
 
 b = contract.Bar()
 try:
     b.test_prepost(2, -4)
     print "Failed! Inherited preassertion."
-except:
+except RuntimeError:
     pass
 
 
@@ -83,54 +83,54 @@ d = contract.D()
 try:
     d.foo(-1, 1, 1, 1, 1)
     print "Failed! Inherited preassertion (D)."
-except:
+except RuntimeError:
     pass
 try:
     d.foo(1, -1, 1, 1, 1)
     print "Failed! Inherited preassertion (D)."
-except:
+except RuntimeError:
     pass
 try:
     d.foo(1, 1, -1, 1, 1)
     print "Failed! Inherited preassertion (D)."
-except:
+except RuntimeError:
     pass
 try:
     d.foo(1, 1, 1, -1, 1)
     print "Failed! Inherited preassertion (D)."
-except:
+except RuntimeError:
     pass
 try:
     d.foo(1, 1, 1, 1, -1)
     print "Failed! Inherited preassertion (D)."
-except:
+except RuntimeError:
     pass
 
 
 try:
     d.bar(-1, 1, 1, 1, 1)
     print "Failed! Inherited preassertion (D)."
-except:
+except RuntimeError:
     pass
 try:
     d.bar(1, -1, 1, 1, 1)
     print "Failed! Inherited preassertion (D)."
-except:
+except RuntimeError:
     pass
 try:
     d.bar(1, 1, -1, 1, 1)
     print "Failed! Inherited preassertion (D)."
-except:
+except RuntimeError:
     pass
 try:
     d.bar(1, 1, 1, -1, 1)
     print "Failed! Inherited preassertion (D)."
-except:
+except RuntimeError:
     pass
 try:
     d.bar(1, 1, 1, 1, -1)
     print "Failed! Inherited preassertion (D)."
-except:
+except RuntimeError:
     pass
 
 # Namespace
@@ -138,5 +138,5 @@ my = contract.myClass(1)
 try:
     my = contract.myClass(0)
     print "Failed! constructor preassertion"
-except:
+except RuntimeError:
     pass