[cindex.py] Fix comments

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159492 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/bindings/python/clang/cindex.py b/bindings/python/clang/cindex.py
index a3da421..23c1ede 100644
--- a/bindings/python/clang/cindex.py
+++ b/bindings/python/clang/cindex.py
@@ -2206,7 +2206,7 @@
     def getCompileCommands(self, filename):
         """
         Get an iterable object providing all the CompileCommands available to
-        build filename. Raise KeyError if filename is not found in the database.
+        build filename. Returns None if filename is not found in the database.
         """
         return CompilationDatabase_getCompileCommands(self, filename)
 
diff --git a/bindings/python/tests/cindex/test_cdb.py b/bindings/python/tests/cindex/test_cdb.py
index 84ac1f8..38de4b1 100644
--- a/bindings/python/tests/cindex/test_cdb.py
+++ b/bindings/python/tests/cindex/test_cdb.py
@@ -22,7 +22,7 @@
     cdb = CompilationDatabase.fromDirectory(kInputsDir)
 
 def test_lookup_fail():
-    """Check an assertion is raised when file lookup failed"""
+    """Check file lookup failure"""
     cdb = CompilationDatabase.fromDirectory(kInputsDir)
     assert cdb.getCompileCommands('file_do_not_exist.cpp') == None