Allows splicing to work correctly
from issue 211340
>> 3: Discourage using package sets like python3.pkgs "directly"
> I think about 8 years ago I introduced this and it has been a clear mistake. Since then this pattern was copied throughout. We should indeed go to pythonPackages and also move the helpers such as buildEnv and withPackages into the package set, like haskell already had before.
- FRidh
* nixpkgs manual, doc Python: render interpreters in a table
The current paragraph presenting Python interpreters is verbose and hinders clarity. The information provided is well suited to be rendered as a table.
Co-authored-by: Shahar "Dawn" Or <mightyiampresence@gmail.com>
* nixpkgs manual, doc Python: fix typos in interpreters' table
* nixpkgs manual, doc Python: update header in interpreters' table
* nixpkgs manual, doc Python: get rid of empty block code workaround in interpreters' table
---------
Co-authored-by: Shahar "Dawn" Or <mightyiampresence@gmail.com>
Updates all interpreter references with 3.10/3.11, which are the
current version, that we recurse into for their package set.
Update all code examples with an explicit `format` and expand lists
with multiple items as we do in the python package set. Also set
`pythonImportsCheck` where tests are disabled.
without stable ids on headings we cannot generate stable links to these
headings. nrd complains about this, but the current docbook workflow
does not.
a few generated ids remain, mostly in examples and footnotes. most of
the examples are generated by nixdoc (which has since gained MD export
functions, and the MD export does generate IDs).
It won't be enough to fix cross in all cases, but it is in at least
one: pywayland. I've only made the change in cases I'm confident it's
correct, as it would be wrong to change this when python.interpreter
is used in wrappers, and possibly when it's used for running tests.
The name should end in Array per the current conventions.
This change also contains some minor formatting fixes, as the heading
levels were inconsistent.
The nixpkgs manual contains references to both sri hash and explicit
sha256 attributes. This is at best confusing to new users. Since the
final destination is exclusive use of sri hashes, see nixos/rfcs#131,
might as well push new users in that direction gently.
Notable exceptions to sri hash support are builtins.fetchTarball,
cataclysm-dda, coq, dockerTools.pullimage, elixir.override, and
fetchCrate. None, other than builtins.fetchTarball, are fundamentally
incompatible, but all currently accept explicit sha256 attributes as
input. Because adding backwards compatibility is out of scope for this
change, they have been left intact, but migration to sri format has been
made for any using old hash formats.
All hashes have been manually tested to be accurate, and updates were
only made for missing upstream artefacts or bugs.
Python package sets can be overridden by overriding an interpreter
and passing in `packageOverrides = self: super: {...};`. This is fine
in case you need a single interpreter, however, it does not help you
when you want to override all sets.
With this change it is possible to override all sets at once by
appending a list of "extensions" to `pythonPackagesExtensions`.
From reading the implementation you might wonder why a list is used, and
not
`lib.composeExtensions`? The reason is the latter requires knowledge of
the library function. This approach should be easier for most users
as it is similar to how we append to lists of e.g. inputs or patches
when overriding a derivation.
We are still using Pandoc’s Markdown parser, which differs from CommonMark spec slightly.
Notably:
- Line breaks in lists behave differently.
- Admonitions do not support the simpler syntax https://github.com/jgm/commonmark-hs/issues/75
- The auto_identifiers uses a different algorithm – I made the previous ones explicit.
- Languages (classes) of code blocks cannot contain whitespace so we have to use “pycon” alias instead of Python “console” as GitHub’s linguist
While at it, I also fixed the following issues:
- ShellSesssion was used
- Removed some pointless docbook tags.
The distinction between the inputs doesn't really make sense in the
mkShell context. Technically speaking, we should be using the
nativeBuildInputs most of the time.
So in order to make this function more beginner-friendly, add "packages"
as an attribute, that maps to nativeBuildInputs.
This commit also updates all the uses in nixpkgs.
I used the existing anchors generated by Docbook, so the anchor part
should be a no-op. This could be useful depending on the
infrastructure we choose to use, and it is better to be explicit than
rely on Docbook's id generating algorithms.
I got rid of the metadata segments of the Markdown files, because they
are outdated, inaccurate, and could make people less willing to change
them without speaking with the author.
Based on some feedback in #87094 and discussion with @fridh, this re-organizes
the onboarding tutorial in the Nixpkgs manual's python section, so that we start
with the simplest, most ad-hoc examples and work our way up. This progresses
from:
1. How to create an temporary python env at the cmdline, then
2. How to create a specific python env for a single script, then
3. How to create a specific python env for a project in a shell.nix, then
4. How to install a specific python env globally on the system or in a user profile.
Additionally, I've tried to standardize on some of the "best practice" ways of
doing things:
1. Instead of saying that this command style is "supported but strongly not
discouraged", I've just deleted it to avoid confusion.
Bad: nix-shell -p python38Packages.numpy python38Packages.toolz
Good: nix-shell -p 'python38.withPackages(ps: with ps; [ numpy toolz ])'
2. In the portion where we show how to add stuff to the user's
`XDG_CONFIG_HOME`, use overlays instead of `config.nix`. The former can do
everything the latter can do, but is also much more generic and powerful,
because it can compose with other files, compose with other envs, compose
with overlays that do things like swap whether tensorflow and pytorch are
built openblas/mkl/cuda stacks, and so on. The user is eventually going to
see the overlay, so to avoid confusion let's standardize on it.
An overlay by any other name would function just as well, but we generally use
`self: super:` for the regular overlays, and `python-self: python-super`.
No material changes to docs, but trying to sanitize them for consistent
readability prior to looking at #75837.
- Use `*` for lists instead of `-`. I have no opinion one way or the other, but
the latter was only used in 1-2 places.
- Pad the code blocks with whitespace.
- Wrap to 80 characters, except for a few 1-liners that were only slightly over.
When updating the section to python 3 some places still
referred to pythonPackages and were overlooked.
Decided to switch it to be more similar to the first
example binding pythonPackages and clarified comments a
bit based on confusion I observed on IRC.
Related to https://github.com/NixOS/nixpkgs/pull/77569
Updating section about imperative use of ad-hoc virtual-environments for
use of pythons built-in `venv` module via venvShellHook. Also trying to
make it a bit friendlier to beginners by adding a bit more explanation
to the code snippet and some remarks old-school virtualenv.
Adjusting for venvShellHook and adding manual example
Adding pip install and replacing python2 example with python3
