Python: implement new codegen

Generated python code now only depends on sqlalchemy. Query functions
are now inside classes as well.

Author: Robert Holt

examples/python/requirements.txt

@@ -2,4 +2,4 @@ pytest~=6.2.2
 pytest-asyncio~=0.14.0
 psycopg2-binary~=2.8.6
 asyncpg~=0.21.0
-sqlalchemy==1.4.0b3
+sqlalchemy==1.4.0

examples/python/sqlc.json

@@ -8,7 +8,9 @@
       "gen": {
         "python": {
           "out": "src/authors",
-          "package": "authors"
+          "package": "authors",
+          "emit_sync_querier": true,
+          "emit_async_querier": true
         }
       }
     },
@@ -19,7 +21,8 @@
       "gen": {
         "python": {
           "out": "src/booktest",
-          "package": "booktest"
+          "package": "booktest",
+          "emit_async_querier": true
         }
       }
     },
@@ -30,7 +33,8 @@
       "gen": {
         "python": {
           "out": "src/jets",
-          "package": "jets"
+          "package": "jets",
+          "emit_async_querier": true
         }
       }
     },
@@ -41,7 +45,8 @@
       "gen": {
         "python": {
           "out": "src/ondeck",
-          "package": "ondeck"
+          "package": "ondeck",
+          "emit_async_querier": true
         }
       }
     }

examples/python/src/authors/models.py

@@ -1,11 +1,11 @@
 # Code generated by sqlc. DO NOT EDIT.
 from typing import Optional
+
 import dataclasses
 
 
-# Enums
 
-# Models
+
 @dataclasses.dataclass()
 class Author:
     id: int

examples/python/src/authors/query.py

@@ -1,3 +1,4 @@
+
 # Code generated by sqlc. DO NOT EDIT.
 from typing import AsyncIterator, Iterator, Optional
 
@@ -35,43 +36,76 @@
 """
 
 
-class Query:
+class Querier:
     def __init__(self, conn: sqlalchemy.engine.Connection):
         self._conn = conn
 
-    def create_author(self, name: str, bio: Optional[str]) -> Optional[models.Author]:
-        result = self._conn.execute(sqlalchemy.text(CREATE_AUTHOR), {"p1": name, "p2": bio})
-        return models.Author(**dict(result.first()))
-
-    def delete_author(self, id: int) -> None:
+    def create_author(self, *, name: str, bio: Optional[str]) -> Optional[models.Author]:
+        row = self._conn.execute(sqlalchemy.text(CREATE_AUTHOR), {"p1": name, "p2": bio}).first()
+        if row is None:
+            return None
+        return models.Author(
+            id=row[0],
+            name=row[1],
+            bio=row[2],
+        )
+
+    def delete_author(self, *, id: int) -> None:
         self._conn.execute(sqlalchemy.text(DELETE_AUTHOR), {"p1": id})
 
-    def get_author(self, id: int) -> Optional[models.Author]:
-        result = self._conn.execute(sqlalchemy.text(GET_AUTHOR), {"p1": id})
-        return models.Author(**dict(result.first()))
+    def get_author(self, *, id: int) -> Optional[models.Author]:
+        row = self._conn.execute(sqlalchemy.text(GET_AUTHOR), {"p1": id}).first()
+        if row is None:
+            return None
+        return models.Author(
+            id=row[0],
+            name=row[1],
+            bio=row[2],
+        )
 
     def list_authors(self) -> Iterator[models.Author]:
         result = self._conn.execute(sqlalchemy.text(LIST_AUTHORS))
         for row in result:
-            yield models.Author(**dict(row))
+            yield models.Author(
+                id=row[0],
+                name=row[1],
+                bio=row[2],
+            )
 
 
-class AsyncQuery:
+class AsyncQuerier:
     def __init__(self, conn: sqlalchemy.ext.asyncio.AsyncConnection):
         self._conn = conn
 
-    async def create_author(self, name: str, bio: Optional[str]) -> Optional[models.Author]:
-        result = await self._conn.execute(sqlalchemy.text(CREATE_AUTHOR), {"p1": name, "p2": bio})
-        return models.Author(**dict(result.first()))
-
-    async def delete_author(self, id: int) -> None:
+    async def create_author(self, *, name: str, bio: Optional[str]) -> Optional[models.Author]:
+        row = (await self._conn.execute(sqlalchemy.text(CREATE_AUTHOR), {"p1": name, "p2": bio})).first()
+        if row is None:
+            return None
+        return models.Author(
+            id=row[0],
+            name=row[1],
+            bio=row[2],
+        )
+
+    async def delete_author(self, *, id: int) -> None:
         await self._conn.execute(sqlalchemy.text(DELETE_AUTHOR), {"p1": id})
 
-    async def get_author(self, id: int) -> Optional[models.Author]:
-        result = await self._conn.execute(sqlalchemy.text(GET_AUTHOR), {"p1": id})
-        return models.Author(**dict(result.first()))
+    async def get_author(self, *, id: int) -> Optional[models.Author]:
+        row = (await self._conn.execute(sqlalchemy.text(GET_AUTHOR), {"p1": id})).first()
+        if row is None:
+            return None
+        return models.Author(
+            id=row[0],
+            name=row[1],
+            bio=row[2],
+        )
 
     async def list_authors(self) -> AsyncIterator[models.Author]:
         result = await self._conn.stream(sqlalchemy.text(LIST_AUTHORS))
         async for row in result:
-            yield models.Author(**dict(row))
+            yield models.Author(
+                id=row[0],
+                name=row[1],
+                bio=row[2],
+            )
+

examples/python/src/booktest/models.py

@@ -3,22 +3,24 @@
 import datetime
 import enum
 
-import pydantic
+import dataclasses
+
 
 
-# Enums
 class BookType(str, enum.Enum):
     FICTION = "FICTION"
     NONFICTION = "NONFICTION"
 
 
-# Models
-class Author(pydantic.BaseModel):
+@dataclasses.dataclass()
+class Author:
     author_id: int
     name: str
 
 
-class Book(pydantic.BaseModel):
+
+@dataclasses.dataclass()
+class Book:
     book_id: int
     author_id: int
     isbn: str