feat(python): extract database initialisation logic from routes.py to db.py

Fix #28

Author: php-coder

README.md

@@ -49,7 +49,7 @@ Generates the endpoints (or a whole app) from a mapping (SQL query -> URL)
    | -----------| ----------------------------| ---------------------------| --------- |
    | JavaScript | `npx query2app --lang js`   | [`app.js`](examples/js/app.js)<br/>[`routes.js`](examples/js/routes.js)<br/>[`package.json`](examples/js/package.json) | Web: [`express`](https://www.npmjs.com/package/express), [`body-parser`](https://www.npmjs.com/package/body-parser)<br>Database: [`mysql`](https://www.npmjs.com/package/mysql) |
    | Golang     | `npx query2app --lang go`   | [`app.go`](examples/go/app.go)<br/>[`routes.go`](examples/go/routes.go)<br/>[`go.mod`](examples/go/go.mod) | Web: [`go-chi/chi`](https://github.com/go-chi/chi)<br/>Database: [`go-sql-driver/mysql`](https://github.com/go-sql-driver/mysql), [`jmoiron/sqlx`](https://github.com/jmoiron/sqlx) |
-   | Python     | `npx query2app --lang python` | [`app.py`](examples/python/app.py)<br/>[`routes.py`](examples/python/routes.py)<br/>[`requirements.txt`](examples/python/requirements.txt) | Web: [FastAPI](https://github.com/tiangolo/fastapi), [Uvicorn](https://www.uvicorn.org)<br/>Database: [psycopg2](https://pypi.org/project/psycopg2/) |
+   | Python     | `npx query2app --lang python` | [`app.py`](examples/python/app.py)<br/>[`db.py`](examples/python/db.py)<br/>[`routes.py`](examples/python/routes.py)<br/>[`requirements.txt`](examples/python/requirements.txt) | Web: [FastAPI](https://github.com/tiangolo/fastapi), [Uvicorn](https://www.uvicorn.org)<br/>Database: [psycopg2](https://pypi.org/project/psycopg2/) |
 
 1. Run the application
    | Language   | Commands to run the application |

examples/python/db.py

@@ -0,0 +1,11 @@
+import os
+import psycopg2
+
+
+async def db_connection():
+    return psycopg2.connect(
+        database=os.getenv('DB_NAME'),
+        user=os.getenv('DB_USER'),
+        password=os.getenv('DB_PASSWORD'),
+        host=os.getenv('DB_HOST', 'localhost'),
+        port=5432)

examples/python/routes.py

@@ -1,19 +1,11 @@
-import os
 import psycopg2
 import psycopg2.extras
 
 from fastapi import APIRouter, Depends, HTTPException
 
-router = APIRouter()
-
+from db import db_connection
 
-async def db_connection():
-    return psycopg2.connect(
-        database=os.getenv('DB_NAME'),
-        user=os.getenv('DB_USER'),
-        password=os.getenv('DB_PASSWORD'),
-        host=os.getenv('DB_HOST', 'localhost'),
-        port=5432)
+router = APIRouter()
 
 
 @router.get('/v1/categories/count')

src/cli.js

@@ -88,9 +88,21 @@ const createApp = async (destDir, lang) => {
     console.log('Generate', fileName);
     const resultFile = path.join(destDir, fileName);
 
-    fs.copyFileSync(`${__dirname}/templates/app.${ext}`, resultFile)
+    fs.copyFileSync(`${__dirname}/templates/${fileName}`, resultFile)
 };
 
+const createDb = async (destDir, lang) => {
+    if (lang !== 'python') {
+        return
+    }
+    const fileName = 'db.py'
+    console.log('Generate', fileName);
+    const resultFile = path.join(destDir, fileName);
+
+    // @todo #28 Create db.py with async API
+    fs.copyFileSync(`${__dirname}/templates/${fileName}`, resultFile)
+}
+
 // "-- comment\nSELECT * FROM foo" => "SELECT * FROM foo"
 const removeComments = (query) => query.replace(/--.*\n/g, '');
 
@@ -330,6 +342,7 @@ if (!fs.existsSync(destDir)) {
 }
 
 createApp(destDir, argv.lang, config);
+createDb(destDir, argv.lang)
 createEndpoints(destDir, argv.lang, config);
 createDependenciesDescriptor(destDir, argv.lang);
 showInstructions(argv.lang);

src/templates/db.py

@@ -0,0 +1,11 @@
+import os
+import psycopg2
+
+
+async def db_connection():
+    return psycopg2.connect(
+        database=os.getenv('DB_NAME'),
+        user=os.getenv('DB_USER'),
+        password=os.getenv('DB_PASSWORD'),
+        host=os.getenv('DB_HOST', 'localhost'),
+        port=5432)

src/templates/routes.py.ejs

@@ -1,19 +1,11 @@
-import os
 import psycopg2
 import psycopg2.extras
 
 from fastapi import APIRouter, Depends, HTTPException
 
-router = APIRouter()
-
+from db import db_connection
 
-async def db_connection():
-    return psycopg2.connect(
-        database=os.getenv('DB_NAME'),
-        user=os.getenv('DB_USER'),
-        password=os.getenv('DB_PASSWORD'),
-        host=os.getenv('DB_HOST', 'localhost'),
-        port=5432)
+router = APIRouter()
 <%
 // { "get", "/v1/categories/:categoryId" } => "get_v1_categories_category_id"
 function generate_method_name(method, path) {