Use fetch_language to coerce python config

lib/cc/engine/analyzers/engine_config.rb

@@ -30,10 +30,6 @@ def mass_threshold_for(language)
           end
         end
 
-        private
-
-        attr_reader :config
-
         def fetch_language(language)
           language = config.
             fetch("languages", {}).
@@ -46,6 +42,10 @@ def fetch_language(language)
           end
         end
 
+        private
+
+        attr_reader :config
+
         def normalize(hash)
           hash.tap do |config|
             languages = config.fetch("config", {}).fetch("languages", {})

lib/cc/engine/analyzers/python/main.rb

@@ -27,7 +27,7 @@ def parser(path)
           end
 
           def python_version
-            engine_config.languages.fetch("python", {}).fetch("python_version", DEFAULT_PYTHON_VERSION)
+            engine_config.fetch_language(LANGUAGE).fetch("python_version", DEFAULT_PYTHON_VERSION)
           end
         end
       end

spec/cc/engine/analyzers/python/main_spec.rb

@@ -117,6 +117,23 @@ def c(thing: str):
     end
   end
 
+  it "handles an empty yml key in config" do
+      create_source_file("foo.py", <<-EOPY)
+def a(thing):
+  print("Hello", thing)
+      EOPY
+
+      conf = CC::Engine::Analyzers::EngineConfig.new({
+      "config" => {
+        "languages" => {
+          "python" => ""
+        }
+      }
+    })
+
+    expect(run_engine(engine_conf)).to eq("")
+  end
+
   def engine_conf
     CC::Engine::Analyzers::EngineConfig.new({
       "config" => {