Fixes enum naming bug

modules/openapi-json-schema-generator/src/main/java/org/openapitools/codegen/languages/PythonClientCodegen.java

@@ -1273,7 +1273,10 @@ public String toEnumVarName(String value, String datatype) {
         // Replace " " with _
         String usedValue = value.replaceAll("\\s+", "_");
         // strip first character if it is invalid
+        int lengthBeforeFirstCharStrip = usedValue.length();
+        Character firstChar = usedValue.charAt(0);
         usedValue = usedValue.replaceAll("^[^_a-zA-Z]", "");
+        boolean firstCharStripped = usedValue.length() == lengthBeforeFirstCharStrip - 1;
         // Replace / with _ for path enums
         usedValue = usedValue.replaceAll("/", "_");
         // Replace . with _ for tag enums
@@ -1296,6 +1299,14 @@ public String toEnumVarName(String value, String datatype) {
             // remove trailing _
             usedValue = usedValue.replaceAll("[_]$", "");
         }
+        // check first character to see if it is valid
+        // if not then add a valid prefix
+        boolean validFirstChar = Pattern.matches("^[_a-zA-Z]", usedValue.substring(0,1));
+        if (!validFirstChar && firstCharStripped) {
+            String charName = Character.getName(firstChar.hashCode());
+            usedValue = charNameToVarName(charName) + "_" + usedValue;
+        }
+
         return usedValue;
     }
 

modules/openapi-json-schema-generator/src/test/java/org/openapitools/codegen/python/PythonClientTest.java

@@ -23,6 +23,8 @@
 import org.openapitools.codegen.*;
 import org.openapitools.codegen.config.CodegenConfigurator;
 import org.openapitools.codegen.languages.PythonClientCodegen;
+import org.openapitools.codegen.model.ModelMap;
+import org.openapitools.codegen.model.ModelsMap;
 import org.openapitools.codegen.utils.ModelUtils;
 import org.testng.Assert;
 import org.testng.annotations.Test;
@@ -32,6 +34,7 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -197,4 +200,28 @@ public void testRegexWithMultipleFlagsWorks() {
         Assert.assertEquals(cm.vendorExtensions.get("x-regex"), expectedRegexPattern);
         Assert.assertEquals(cm.vendorExtensions.get("x-modifiers"), Arrays.asList("DOTALL", "IGNORECASE", "MULTILINE"));
     }
+
+    @Test
+    public void testEnumNames() {
+        OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/70_schema_enum_names.yaml");
+        PythonClientCodegen codegen = new PythonClientCodegen();
+        codegen.setOpenAPI(openAPI);
+
+        String modelName = "StringEnum";
+        Schema schema = openAPI.getComponents().getSchemas().get(modelName);
+
+        CodegenModel cm = codegen.fromModel(modelName, schema);
+
+        ModelMap modelMap = new ModelMap();
+        modelMap.setModel(cm);
+
+        ModelsMap modelsMap = new ModelsMap();
+        modelsMap.setModels(Collections.singletonList(modelMap));
+        codegen.postProcessModels(modelsMap);
+
+        ArrayList<Map<String, Object>> enumVars = (ArrayList<Map<String, Object>>) cm.getAllowableValues().get("enumVars");
+        Assert.assertEquals(enumVars.size(), 2);
+        Assert.assertEquals(enumVars.get(0).get("name"), "DIGIT_THREE_67B9C");
+        Assert.assertEquals(enumVars.get(1).get("name"), "FFA5A4");
+    }
 }

modules/openapi-json-schema-generator/src/test/resources/3_0/70_schema_enum_names.yaml

@@ -0,0 +1,12 @@
+openapi: 3.0.3
+info:
+  title: Test
+  version: 1.0.0-SNAPSHOT
+paths: {}
+components:
+  schemas:
+    StringEnum:
+      type: string
+      enum:
+        - "#367B9C"
+        - "#FFA5A4"