added support for pascal case on aliases functions

Author: phenobarbital

datamodel/aliases/__init__.py

@@ -10,7 +10,17 @@ def to_snakecase(name: str) -> str:
     Convert a CamelCase or PascalCase string into snake_case.
     Example: "EmailAddress" -> "email_address"
     """
-    import re
     # Insert underscores before capital letters, then lower-case
     s1 = _RE_FIRST_CAP.sub(r"\1_\2", name)
     return _RE_ALL_CAPS.sub(r"\1_\2", s1).lower()
+
+
+def to_pascalcase(s: str) -> str:
+    """
+    Convert a snake_case string into PascalCase.
+    Example:
+        store_id -> StoreId
+        email_address -> EmailAddress
+    """
+    parts = s.split("_")
+    return "".join(word.capitalize() for word in parts)

examples/test_aliases.py

@@ -1,6 +1,6 @@
 from typing import List, Optional
 from datamodel import BaseModel, Field
-from datamodel.aliases import to_snakecase
+from datamodel.aliases import to_snakecase, to_pascalcase
 
 
 class Store(BaseModel):
@@ -13,6 +13,37 @@ class Meta:
         as_objects = True
         alias_function = to_snakecase
 
-# Example Usage:
-store = Store(EmailAddress="[email protected]", Status="ACTIVE", StoreId=1)
-print(store)
+
+
+class ExampleModel(BaseModel):
+    # Here, our Python fields are declared in PascalCase.
+    StoreId: int = Field(primary_key=True)
+    EmailAddress: str
+    Status: str
+
+    class Meta:
+        strict = True
+        as_objects = True
+        # Our alias_function now transforms from the incoming snake_case to PascalCase.
+        # So if user passes `store_id`, we transform it to `StoreId`.
+        alias_function = to_pascalcase
+
+def demo():
+    store = Store(EmailAddress="[email protected]", Status="ACTIVE", StoreId=1)
+    print("StoreId =>", store.store_id)
+    print("EmailAddress =>", store.email_address)
+    # The user input is using snake_case:
+    model = ExampleModel(
+        store_id=123,
+        email_address="[email protected]",
+        status="ACTIVE"
+    )
+    # Internally, we have PascalCase attributes:
+    print("StoreId =>", model.StoreId)
+    print("EmailAddress =>", model.EmailAddress)
+    print("Status =>", model.Status)
+    # Check the actual model
+    print(model)
+
+if __name__ == "__main__":
+    demo()