Hi, I work at Machinalis were we use a lot of numpy (and the pydata stack in general). Recently we've also been getting involved with mypy, which is a tool to type check (not on runtime, think of it as a linter) annotated python code (the way of annotating python types has been recently standarized in PEP 484). As part of that involvement we've started creating type annotations for the Python libraries we use most, which include numpy. Mypy provides a way to specify types with annotations in separate files in case you don't have control over a library, so we have created an initial proof of concept at [1], and we are actively improving it. You can find some additional information about it and some problems we've found on the way at this blogpost [2]. What I wanted to ask is if the people involved on the numpy project are aware of PEP484 and if you have some interest in starting using them. The main benefit is that annotations serve as clear (and automatically testable) documentation for users, and secondary benefits is that users discovers bugs more quickly and that some IDEs (like pycharm) are starting to use this information for smart editor features (autocompletion, online checking, refactoring tools); eventually tools like jupyter could take advantage of these annotations in the future. And the cost of writing and including these are relatively low. We're doing the work anyway, but contributing our typespecs back could make it easier for users to benefit from this, and for us to maintain it and keep it in sync with future releases. If you've never heard about PEP484 or mypy (it happens a lot) I'll be happy to clarify anything about it that might helpunderstand this situation Thanks! D. [1] https://github.com/machinalis/mypy-data [2] http://www.machinalis.com/blog/writing-type-stubs-for-numpy/ -- Daniel F. Moisset - UK Country Manager www.machinalis.com Skype: @dmoisset