fix: generate proper python identifiers when generating model from sc…

…hemas. Related to #628 (#639)

dataclasses_avroschema/model_generator/lang/python/base.py

@@ -186,7 +186,7 @@ def render_field(self, field: JsonDict, model_name: str) -> FieldRepresentation:
         3. If the field is a LogicalType, it may not have the
             the `name` property and the type is a `native` one
         """
-        name = field.get("name", "")
+        name = self.generate_field_name(field.get("name", ""))
         type: AvroTypeRepr = field["type"]
         default = field.get("default", dataclasses.MISSING)
         field_metadata = self.get_field_metadata(field)
@@ -255,6 +255,12 @@ def render_field(self, field: JsonDict, model_name: str) -> FieldRepresentation:
 
         return FieldRepresentation(name=name, string_representation=result, has_default=has_default)
 
+    @staticmethod
+    def generate_field_name(field_name: str) -> str:
+        if field_name and not field_name.isidentifier():
+            return casefy.snakecase(field_name)
+        return field_name
+
     @staticmethod
     def is_logical_type(*, field: JsonDict) -> bool:
         if field.get("logicalType"):

docs/model_generator.md

@@ -360,6 +360,48 @@ print(User.fake())
 # >>> User(name='JBZdhEWdXwFLQitWCjkc', age=3406, address=Address(name='AhlQsvXnkpcPZJvRSXLr'))
 ```
 
+## Schema with invalid python identifiers
+
+`avro schemas` could contain field names that are not valid `python identifiers`, for example `street-name`. If we have the following `avro schema` the `python model` generated from it will generate `valid identifiers`, in this case and `street_name`  and `street_number`
+
+```python
+from dataclasses_avroschema import ModelGenerator
+
+
+schema = {
+    "type": "record",
+    "name": "Address",
+    "fields": [
+        {"name": "street-name", "type": "string"},
+        {"name": "street-number", "type": "long"}
+    ]
+}
+
+model_generator = ModelGenerator()
+result = model_generator.render(schema=schema)
+
+# save the result in a file
+with open("models.py", mode="+w") as f:
+    f.write(result)
+```
+
+Then the result will be:
+
+```python
+# models.py
+from dataclasses_avroschema import AvroModel
+import dataclasses
+
+
+@dataclasses.dataclass
+class Address(AvroModel):
+    street_name: str
+    street_number: int
+```
+
+!!! warning
+    If you try to generate the `schema` from the model, both schemas won't match. You might have to use the [case](https://marcosschroh.github.io/dataclasses-avroschema/case/) functionality
+
 ## Field order
 
 Sometimes we have to work with schemas that were created by a third party and we do not have control over them. Those schemas can contain optional fields
@@ -462,7 +504,6 @@ class UnitMultiPlayer(enum.Enum):
 @dataclasses.dataclass
 class User(AvroModel):
     unit_multi_player: UnitMultiPlayer
-
 ```
 
 As the example shows the second enum member `UnitMultiPlayer.p` is not in uppercase otherwise will collide with the first member `UnitMultiPlayer.P`

scripts/test

@@ -8,5 +8,5 @@ fi
 tests=${1-"./tests"}
 
 ${PREFIX}pytest --cov=dataclasses_avroschema ${tests} ${2} --cov-fail-under=99 --cov-report html  --cov-report term-missing  --cov-report xml
-${PREFIX}ruff dataclasses_avroschema tests
+${PREFIX}ruff check dataclasses_avroschema tests
 ${PREFIX}mypy dataclasses_avroschema

tests/model_generator/conftest.py

@@ -44,6 +44,22 @@ def schema_2() -> Dict:
     }
 
 
+@pytest.fixture
+def schema_with_invalid_python_identifiers() -> Dict:
+    return {
+        "type": "record",
+        "name": "Address",
+        "fields": [
+            {"name": "street-name", "type": "string"},
+            {"name": "street-number", "type": "long"},
+            {"name": "ValidIdentifier", "type": "string"},
+            {"name": "anotherIdentifier", "type": "string"},
+            {"name": "_private", "type": "string"},
+        ],
+        "doc": "An Address",
+    }
+
+
 @pytest.fixture
 def schema_primitive_types_as_defined_types() -> Dict:
     return {

tests/model_generator/test_model_generator.py

@@ -36,6 +36,30 @@ class Meta:
     assert result.strip() == expected_result.strip()
 
 
+def test_schema_with_invalid_python_identifiers(schema_with_invalid_python_identifiers: types.JsonDict) -> None:
+    expected_result = """
+from dataclasses_avroschema import AvroModel
+import dataclasses
+
+
+@dataclasses.dataclass
+class Address(AvroModel):
+    \"""
+    An Address
+    \"""
+    street_name: str
+    street_number: int
+    ValidIdentifier: str
+    anotherIdentifier: str
+    _private: str
+
+
+"""
+    model_generator = ModelGenerator()
+    result = model_generator.render(schema=schema_with_invalid_python_identifiers)
+    assert result.strip() == expected_result.strip()
+
+
 def test_model_generator_primitive_types_as_defined_types(
     schema_primitive_types_as_defined_types: types.JsonDict,
 ) -> None: