docs: Update readme

packages/@aws-cdk/aws-lambda-python/README.md

@@ -172,9 +172,9 @@ new lambda.PythonFunction(this, 'function', {
 });
 ```
 
-The index URL or the token are only used during bundling and thus not included in the final asset.
+The index URL or the token are only used during bundling and thus not included in the final asset. Setting only environment variable for `PIP_INDEX_URL` or `PIP_EXTRA_INDEX_URL` should work for accesing private Python repositories with `pip`, `pipenv` and `poetry` based dependencies.
 
-If you also want to use the Code Artifact repo for initializing the Docker image for bundling, use `buildArgs`:
+If you also want to use the Code Artifact repo for building the base Docker image for bundling, use `buildArgs`. However, note that setting custom build args for bundling will force the base bundling image to be rebuilt every time (i.e. skip the Docker cache). Build args can be customized as:
 
 ```ts
 import { execSync } from 'child_process';
@@ -198,34 +198,3 @@ new lambda.PythonFunction(this, 'function', {
  },
 });
 ```
-
-**Note:** Setting custom build args for bundling will force the base bundling image to be rebuilt every time (i.e. skip the Docker cache).
-
-Setting only environment variable should work for `pip` and `poetry` based dependencies, whereas `pipenv` based dependencies will require **both** build args and environment variables to be set.
-
-
-Example for using Code Artifact with `pipenv`-based dependencies:
-
-```ts
-import { execSync } from 'child_process';
-
-const entry = '/path/to/function';
-const image = DockerImage.fromBuild(entry);
-
-const domain = 'my-domain';
-const domainOwner = '111122223333';
-const repoName = 'my_repo';
-const region = 'us-east-1';
-const codeArtifactAuthToken = execSync(`aws codeartifact get-authorization-token --domain ${domain} --domain-owner ${domainOwner} --query authorizationToken --output text`).toString().trim();
-
-const indexUrl = `https://aws:${codeArtifactAuthToken}@${domain}-${domainOwner}.d.codeartifact.${region}.amazonaws.com/pypi/${repoName}/simple/`;
-
-new lambda.PythonFunction(this, 'function', {
- entry,
- runtime: Runtime.PYTHON_3_8,
- bundling: {
- buildArgs: { PIP_INDEX_URL: indexUrl },
- environment: { PIP_INDEX_URL: indexUrl },
- },
-});
-```