fix(ModelGenerator): Rename fields named after Python keywords (#870)

We now append an "_" to any fields that are Python keywords in order to
still generate valid Python code.

Co-authored-by: George Ungureanu Vranceanu <george.ungureanuvranceanu@imc.com>

Author: Gungy2

dataclasses_avroschema/model_generator/lang/python/base.py

@@ -1,6 +1,7 @@
 import copy
 import dataclasses
 import json
+import keyword
 import typing
 from abc import abstractmethod
 from dataclasses import dataclass, field
@@ -527,19 +528,29 @@ def render_field(self, field: JsonDict, model_name: str, parent_field_name: str)
     @staticmethod
     def generate_field_name(field: JsonDict) -> str:
         field_name = field.get("name", "")
+        if not field_name:
+            return field_name
 
-        if field_name and not field_name.isidentifier():
+        if keyword.iskeyword(field_name):
+            valid_identifier = f"{field_name}_"
+            BaseGenerator.maybe_add_alias(field, field_name)
+            return valid_identifier
+
+        if not field_name.isidentifier():
             valid_identifier = casefy.snakecase(field_name)
             if valid_identifier != field_name:
-                aliases = field.get("aliases", [])
-
-                if valid_identifier not in aliases:
-                    aliases.append(field_name)
-                    field["aliases"] = aliases
-
+                BaseGenerator.maybe_add_alias(field, field_name)
             return valid_identifier
         return field_name
 
+    @staticmethod
+    def maybe_add_alias(field: JsonDict, alias: str) -> None:
+        aliases = field.get("aliases", [])
+
+        if alias not in aliases:
+            aliases.append(alias)
+            field["aliases"] = aliases
+
     @staticmethod
     def is_logical_type(*, field: JsonDict) -> bool:
         if field.get("logicalType"):

tests/model_generator/conftest.py

@@ -62,6 +62,20 @@ def schema_with_invalid_python_identifiers() -> Dict:
     }
 
 
+@pytest.fixture
+def schema_with_python_keywords() -> Dict:
+    return {
+        "type": "record",
+        "name": "Address",
+        "fields": [
+            {"name": "class", "type": "string"},
+            {"name": "yield", "type": "string", "aliases": ["yield"]},
+            {"name": "yield_class", "type": "long"},
+        ],
+        "doc": "An Address",
+    }
+
+
 @pytest.fixture
 def schema_primitive_types_as_defined_types() -> Dict:
     return {

tests/model_generator/test_model_pydantic_generator.py

@@ -115,6 +115,28 @@ class Address(AvroBaseModel):
     assert result.strip() == expected_result.strip()
 
 
+def test_avro_pydantic_python_keywords(schema_with_python_keywords: types.JsonDict) -> None:
+    expected_result = """
+from dataclasses_avroschema.pydantic import AvroBaseModel
+import pydantic
+
+
+
+class Address(AvroBaseModel):
+    \"""
+    An Address
+    \"""
+    class_: str = pydantic.Field(metadata={'aliases': ['class']})
+    yield_: str = pydantic.Field(metadata={'aliases': ['yield']})
+    yield_class: int
+
+
+"""
+    model_generator = ModelGenerator()
+    result = model_generator.render(schema=schema_with_python_keywords, model_type=ModelType.AVRODANTIC.value)
+    assert result.strip() == expected_result.strip()
+
+
 def test_avro_pydantic_model_with_meta_fields(
     schema_one_to_self_relationship: types.JsonDict,
 ) -> None: