Re: [PATCH] import: pypi: read requirements from wheels.

[Ludovic Courtès]

Cyril Roelandt <address@hidden> skribis:

> * guix/import/pypi.scm (latest-wheel-release): New function.

s/function/procedure/  :-)

Please also mention the changes in ‘guess-requirements’,
‘compute-inputs’, etc.

So do I get it right that pypi now provides packages both in Wheels and
in “traditional” format, but that Wheels provides more info about
dependencies?

IOW: What does this buy us?  :-)

> +(define (latest-wheel-release pypi-package)
> +  "Return the url of the wheel for the latest release of pypi-package, of #f 
> if

Line a bit long.  s/of/or/

> +  (define (read-wheel-metadata wheel-archive)
> +    ;; Given WHEEL-ARCHIVE, a ZIP Python wheel archive, return the package's
> +    ;; requirements.
> +    (let* ((dirname (string-append
> +                     (string-join
> +                      (list-head
> +                       (string-split (last (string-split wheel-url #\/))  
> #\-) 2)
> +                        "-")

"-" should be aligned with (list-head.

I would be best to turn this transformation into a top-level procedure,
say ‘wheel-url->extracted-directory’.

> +                     ".dist-info"))
> +           (json-file (string-append dirname "/metadata.json")))
> +      (and (system* "unzip" "-q" wheel-archive json-file)
> +           (dynamic-wind
> +             (const #t)
> +             (lambda ()
> +               (call-with-input-file json-file
> +                 (lambda (port)
> +                   (let* ((metadata (json->scm port))
> +                          (run_requires (hash-ref metadata "run_requires"))
> +                          (requirements (hash-ref (list-ref run_requires 0)
> +                                                  "requires")))
> +                     (map (lambda (r)
> +                            (python->package-name (clean-requirement r)))
> +                          requirements)))))
> +             (lambda ()
> +               (delete-file json-file)
> +               (rmdir dirname))))))

Eventually I wonder if we should do this in a derivation instead of
hoping for ‘unzip’ & co. to be available there (“eventually”, because
the problem is already present with the ‘requirements.txt’ thingie.)

Could you add a test in tests/pypi.scm?

Thanks!

Ludo’.