psycopg2cffi VS direnv

The only compatibility issue I've run into is database drivers.

For PostgreSQL, psycopg2 is not supported. psycopg2cffi is largely unmaintained, and the 2.9.0 version in PyPI lacks some newer features of psycopg2: the `psycopg2.sql` module and empty result sets raise a RuntimeError in Python 3.7+. The latest commit in on Github does have these changes [1]. Psycopg 3 [2] and pg8000 [3] (as user tlocke mentioned elsewhere) are viable alternates provided you aren't stuck with older versions of PostgreSQL. I'm going to continue to use psycopg2cffi until I can upgrade an old PostgreSQL 9.4 database.

For Microsoft SQL Server, pymssql does not support PyPy [4]. It's under new maintainership so it might gain support in the future. pypyodbc hasn't had any activity since 2022, and no new PyPI release since 2021 [5]. The datatypes returned can differ between libodbc1 versions. On Ubuntu 18.04 in particular: empty string columns are returned as a single space, integer columns are returned as a Decimal. Also, if you encounter a mysterious HY010 error ("Function sequence error"), you may need to upgrade libodbc1 to v2.3.7+ from v2.3.4 using the Microsoft repos.

[1]: https://github.com/chtd/psycopg2cffi

From time to time, I use pgcopy coupled with psycopg2cffi to feed large volumes of data processed by custom parsers written in Python for several formats. The whole process is 4-5x faster with PyPy.

I think direnv already does a good job in this space, and it's already available in your package manager.

https://direnv.net/

I switched from asdf to mise after a comment on lobste.rs[1] suggested I do so a few months ago, and I have been very happy with it.

It sands off some of asdf's sharp UI edges and provides a somewhat larger but still reasonable feature set; I've also replaced most of my direnv[2] usage with it.

The mise -> asdf comparison page is useful[3]

1: https://lobste.rs/s/66uxbj/how_love_homebrew#c_mvmsjp

2: https://direnv.net/

3: https://mise.jdx.dev/dev-tools/comparison-to-asdf.html

I also made the export diff configurable, motivated by this post: https://github.com/direnv/direnv/pull/1233

Nice.

For years I've been using [direnv](https://direnv.net/) for this, setting environment variables which git picks up. This looks like a more feature complete equivalent, although to be honest I only really need switching of committer email and the SSH key used.

Direnv, for the uninitiated, loads and unloads environment variables when directories are entered and exited. Under every project folder there is a `$PROJ_DIR/.envrc` which contains:

buffer-env: A pure-Elisp version of the direnv utility. Useful to make Emacs aware of Python virtualenvs (which, judging by the questions posted here, is unfortunately still a complication for a lot of people). Similar to (and inspired by) envrc, but doesn't require the direnv program.

You can look at direnv to see this in action as they wrote shell hooks that get loaded into the shell profile and are executed on every prompt. https://direnv.net/

Yes, most Nix users employ https://direnv.net or the equivalent for your IDE of choice. Emacs for instance has https://github.com/purcell/envrc which set per-buffer variables.