make sure only parent is imported

Author: HugoMario

src/main/java/io/swagger/codegen/v3/generators/python/PythonClientCodegen.java

@@ -29,6 +29,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 import static io.swagger.codegen.v3.generators.handlebars.ExtensionHelper.getBooleanValue;
 
@@ -239,6 +240,17 @@ public void processOpts() {
 
     }
 
+    @Override
+    public CodegenModel fromModel(String name, Schema schema, Map<String, Schema> allDefinitions) {
+        final CodegenModel codegenModel = super.fromModel(name, schema, allDefinitions);
+        final List<String> imports = codegenModel.imports.stream()
+                .filter(model -> model.equals(codegenModel.parent))
+                .collect(Collectors.toList());
+        codegenModel.imports.clear();
+        codegenModel.imports.addAll(imports);
+        return codegenModel;
+    }
+
     private static String dropDots(String str) {
         return str.replaceAll("\\.", "_");
     }