yapf tools/interop_matrix
diff --git a/tools/interop_matrix/client_matrix.py b/tools/interop_matrix/client_matrix.py
index 7281307..f32bdf8 100644
--- a/tools/interop_matrix/client_matrix.py
+++ b/tools/interop_matrix/client_matrix.py
@@ -15,29 +15,34 @@
 
 # Dictionaries used for client matrix testing.
 
+
 def get_github_repo(lang):
-  return {
-      'go': 'git@github.com:grpc/grpc-go.git',
-      'java': 'git@github.com:grpc/grpc-java.git',
-      'node': 'git@github.com:grpc/grpc-node.git',
-      # all other languages use the grpc.git repo.
-  }.get(lang, 'git@github.com:grpc/grpc.git')
+    return {
+        'go': 'git@github.com:grpc/grpc-go.git',
+        'java': 'git@github.com:grpc/grpc-java.git',
+        'node': 'git@github.com:grpc/grpc-node.git',
+        # all other languages use the grpc.git repo.
+    }.get(lang, 'git@github.com:grpc/grpc.git')
+
 
 def get_release_tags(lang):
-  return map(lambda r: get_release_tag_name(r), LANG_RELEASE_MATRIX[lang])
+    return map(lambda r: get_release_tag_name(r), LANG_RELEASE_MATRIX[lang])
+
 
 def get_release_tag_name(release_info):
-  assert len(release_info.keys()) == 1
-  return release_info.keys()[0]
+    assert len(release_info.keys()) == 1
+    return release_info.keys()[0]
+
 
 def should_build_docker_interop_image_from_release_tag(lang):
-  if lang in ['go', 'java', 'node']:
-    return False
-  return True
+    if lang in ['go', 'java', 'node']:
+        return False
+    return True
+
 
 # Dictionary of runtimes per language
 LANG_RUNTIME_MATRIX = {
-    'cxx': ['cxx'],             # This is actually debian8.
+    'cxx': ['cxx'],  # This is actually debian8.
     'go': ['go1.7', 'go1.8'],
     'java': ['java_oracle8'],
     'python': ['python'],
@@ -51,81 +56,197 @@
 # a release tag pointing to the latest build of the branch.
 LANG_RELEASE_MATRIX = {
     'cxx': [
-        {'v1.0.1': None},
-        {'v1.1.4': None},
-        {'v1.2.5': None},
-        {'v1.3.9': None},
-        {'v1.4.2': None},
-        {'v1.6.6': None},
-        {'v1.7.2': None},
+        {
+            'v1.0.1': None
+        },
+        {
+            'v1.1.4': None
+        },
+        {
+            'v1.2.5': None
+        },
+        {
+            'v1.3.9': None
+        },
+        {
+            'v1.4.2': None
+        },
+        {
+            'v1.6.6': None
+        },
+        {
+            'v1.7.2': None
+        },
     ],
     'go': [
-        {'v1.0.5': None},
-        {'v1.2.1': None},
-        {'v1.3.0': None},
-        {'v1.4.2': None},
-        {'v1.5.2': None},
-        {'v1.6.0': None},
-        {'v1.7.4': None},
-        {'v1.8.1': None},
+        {
+            'v1.0.5': None
+        },
+        {
+            'v1.2.1': None
+        },
+        {
+            'v1.3.0': None
+        },
+        {
+            'v1.4.2': None
+        },
+        {
+            'v1.5.2': None
+        },
+        {
+            'v1.6.0': None
+        },
+        {
+            'v1.7.4': None
+        },
+        {
+            'v1.8.1': None
+        },
     ],
     'java': [
-        {'v1.0.3': None},
-        {'v1.1.2': None},
-        {'v1.2.0': None},
-        {'v1.3.1': None},
-        {'v1.4.0': None},
-        {'v1.5.0': None},
-        {'v1.6.1': None},
-        {'v1.7.0': None},
-        {'v1.8.0': None},
+        {
+            'v1.0.3': None
+        },
+        {
+            'v1.1.2': None
+        },
+        {
+            'v1.2.0': None
+        },
+        {
+            'v1.3.1': None
+        },
+        {
+            'v1.4.0': None
+        },
+        {
+            'v1.5.0': None
+        },
+        {
+            'v1.6.1': None
+        },
+        {
+            'v1.7.0': None
+        },
+        {
+            'v1.8.0': None
+        },
     ],
     'python': [
-        {'v1.0.x': None},
-        {'v1.1.4': None},
-        {'v1.2.5': None},
-        {'v1.3.9': None},
-        {'v1.4.2': None},
-        {'v1.6.6': None},
-        {'v1.7.2': None},
+        {
+            'v1.0.x': None
+        },
+        {
+            'v1.1.4': None
+        },
+        {
+            'v1.2.5': None
+        },
+        {
+            'v1.3.9': None
+        },
+        {
+            'v1.4.2': None
+        },
+        {
+            'v1.6.6': None
+        },
+        {
+            'v1.7.2': None
+        },
     ],
     'node': [
-        {'v1.0.1': None},
-        {'v1.1.4': None},
-        {'v1.2.5': None},
-        {'v1.3.9': None},
-        {'v1.4.2': None},
-        {'v1.6.6': None},
+        {
+            'v1.0.1': None
+        },
+        {
+            'v1.1.4': None
+        },
+        {
+            'v1.2.5': None
+        },
+        {
+            'v1.3.9': None
+        },
+        {
+            'v1.4.2': None
+        },
+        {
+            'v1.6.6': None
+        },
         #{'v1.7.1': None}, Failing tests
     ],
     'ruby': [
-        {'v1.0.1': {'patch': [
-            'tools/dockerfile/interoptest/grpc_interop_ruby/Dockerfile',
-            'tools/dockerfile/interoptest/grpc_interop_ruby/build_interop.sh',
-        ]}},
-        {'v1.1.4': None},
-        {'v1.2.5': None},
-        {'v1.3.9': None},
-        {'v1.4.2': None},
-        {'v1.6.6': None},
-        {'v1.7.2': None},
+        {
+            'v1.0.1': {
+                'patch': [
+                    'tools/dockerfile/interoptest/grpc_interop_ruby/Dockerfile',
+                    'tools/dockerfile/interoptest/grpc_interop_ruby/build_interop.sh',
+                ]
+            }
+        },
+        {
+            'v1.1.4': None
+        },
+        {
+            'v1.2.5': None
+        },
+        {
+            'v1.3.9': None
+        },
+        {
+            'v1.4.2': None
+        },
+        {
+            'v1.6.6': None
+        },
+        {
+            'v1.7.2': None
+        },
     ],
     'php': [
-        {'v1.0.1': None},
-        {'v1.1.4': None},
-        {'v1.2.5': None},
-        {'v1.3.9': None},
-        {'v1.4.2': None},
-        {'v1.6.6': None},
-        {'v1.7.2': None},
+        {
+            'v1.0.1': None
+        },
+        {
+            'v1.1.4': None
+        },
+        {
+            'v1.2.5': None
+        },
+        {
+            'v1.3.9': None
+        },
+        {
+            'v1.4.2': None
+        },
+        {
+            'v1.6.6': None
+        },
+        {
+            'v1.7.2': None
+        },
     ],
-   'csharp': [
+    'csharp': [
         #{'v1.0.1': None},
-        {'v1.1.4': None},
-        {'v1.2.5': None},
-        {'v1.3.9': None},
-        {'v1.4.2': None},
-        {'v1.6.6': None},
-        {'v1.7.2': None},
+        {
+            'v1.1.4': None
+        },
+        {
+            'v1.2.5': None
+        },
+        {
+            'v1.3.9': None
+        },
+        {
+            'v1.4.2': None
+        },
+        {
+            'v1.6.6': None
+        },
+        {
+            'v1.7.2': None
+        },
     ],
 }