Simple heuristics to determine python executable name across platforms

packages/aws-cdk/lib/init-templates/app/python/README.md → packages/aws-cdk/lib/init-templates/app/python/README.template.md

@@ -14,13 +14,7 @@ manually once the init process completes.
 To manually create a virtualenv on MacOS and Linux:
 
 ```
-$ python3 -m venv .env
-```
-
-For Windows, use:
-
-```
-% python -m venv .env
+$ %python-executable% -m venv .env
 ```
 
 After the init process completes and the virtualenv is created, you can use the following

packages/aws-cdk/lib/init-templates/app/python/cdk.template.json

@@ -0,0 +1,3 @@
+{
+    "app": "%python-executable% app.py"
+}

packages/aws-cdk/lib/init-templates/sample-app/python/README.md → packages/aws-cdk/lib/init-templates/sample-app/python/README.template.md

@@ -15,13 +15,7 @@ manually once the init process completes.
 To manually create a virtualenv on MacOS and Linux:
 
 ```
-$ python3 -m venv .env
-```
-
-For Windows, use:
-
-```
-% python -m venv .env
+$ %python-executable% -m venv .env
 ```
 
 After the init process completes and the virtualenv is created, you can use the following

packages/aws-cdk/lib/init-templates/sample-app/python/cdk.template.json

@@ -0,0 +1,3 @@
+{
+    "app": "%python-executable% app.py"
+}

packages/aws-cdk/lib/init.ts

@@ -42,6 +42,17 @@ export async function cliInit(type?: string, language?: string, canUseNetwork?:
   await initializeProject(template, language, canUseNetwork !== undefined ? canUseNetwork : true);
 }
 
+/**
+ * 
+ * @returns the name of the Python executable for this OS 
+ */
+function pythonExecutable() {
+  let python = 'python3';
+  if (process.platform == 'win32') {
+    python = 'python';
+  }
+  return python;
+}
 const INFO_DOT_JSON = 'info.json';
 
 export class InitTemplate {
@@ -143,7 +154,8 @@ export class InitTemplate {
              .replace(/%name\.PascalCased%/g, camelCase(project.name, { pascalCase: true }))
              .replace(/%cdk-version%/g, cdkVersion)
              .replace(/%cdk-home%/g, CDK_HOME)
-             .replace(/%name\.PythonModule%/g, project.name.replace(/-/g, '_'));
+             .replace(/%name\.PythonModule%/g, project.name.replace(/-/g, '_'))
+             .replace(/%python-executable%/g, pythonExecutable());
   }
 }
 
@@ -233,7 +245,7 @@ async function postInstall(language: string, canUseNetwork: boolean) {
   case 'java':
     return await postInstallJava(canUseNetwork);
   case 'python':
-    return await postInstallPython(canUseNetwork);
+    return await postInstallPython();
   }
 }
 
@@ -263,18 +275,15 @@ async function postInstallJava(canUseNetwork: boolean) {
   await execute('mvn', 'package');
 }
 
-async function postInstallPython(canUseNetwork: boolean) {
-  if (!canUseNetwork) {
-    print(`Please run ${colors.green('python -m venv .env')}!`);
-    return;
-  }
-
-  print(`Executing ${colors.green('python -m venv .env')}`);
+async function postInstallPython() {
+  const python = pythonExecutable();
+  print(`Executing ${colors.green('Creating virtualenv')}`);
   try {
-    await execute('python3', '-m venv', '.env');
+    await execute(python, '-m venv', '.env');
   } catch (e) {
-    throw new Error(`${colors.green('python3 -m venv .env')} failed: ` + e.message);
-  }
+    print('Unable to create virtualenv automatically');
+    print(`Please run ${colors.green('python3 -m venv .env')}!`);
+    }
 }
 
 /**