Performance with AWS CDK in WSL

[arjentraas]

Developing Python in VS Code with Windows Subsystem for Linux (WSL) is the best Python development experience for me so far.

The only exception is writing infrastructure as code using the Cloud Development Kit (CDK) from Amazon Web Services (AWS). Pylance is struggling a lot to load type hints, auto imports and syntax highlighting. It may take up to 10 seconds to load that kind of stuff. It even crashes if I write to much code in a short time window.

Switching from WSL to Windows helps a bit. Pylance speeds up a little, while other things slow down, so I end up accepting the CDK performance hit and reverting to WSL.

These log entries show up a lot:

[BG(1)] Long operation: analyzing: file:///home/user/sources/my_application/stacks/my_stack.py (2541ms)

Anyone have the same experience? Or even better, a solution?

[rchiodo]

Do you have some example code? We can analyze why it's taking so long. CDK was a problem in the past with taking lots of memory with the amount of docstrings it provided, but I don't recall it being slow.

[rchiodo]

Yeah it's slow for me too.

2025-02-25 09:45:44.323 [info] [Info  - 9:45:44 AM] (22024) [BG(1)] Long operation: analyzing: file:///c%3A/Users/rchiodo/source/testing/test_pylance/.venv/Lib/site-packages/aws_cdk/aws_lambda/__init__.py (3885ms)

There's no real low hanging fruit though. It's just parsing lots and lots of functions. :(

[rchiodo]

Creating an issue

[rchiodo]

#6986

[bschnurr]

could try adding a 'py.typed' file to the aws package folder.. to disable type inference. might help..

nevermind i see there is one.

What is the actual pip package? 'pip install aws-cdk-lib'

[rchiodo]

AWS cdk seems to be typed though. I don't think it's a type inference problem.