build-system/python: Export 'python-version'.

* guix/build/python-build-system.scm (get-python-version): Rename to...
(python-version): ... this.  Update callers.  Make public.
* gnu/packages/gstreamer.scm (python-gst)[arguments]: Adjust accordingly.
* gnu/packages/machine-learning.scm (ghmm)[arguments]: Likewise.
* gnu/packages/openldap.scm (389-ds-base)[arguments]: Import (guix
build python-build-system).  Use 'python-version'.
* gnu/packages/package-management.scm (conda)[arguments]: Use
'python-version'.

4 files changed, 8 insertions, 15 deletions

diff --git a/gnu/packages/gstreamer.scm b/gnu/packages/gstreamer.scm
index 2a818e078c..39a4eb5fc0 100644
--- a/gnu/packages/gstreamer.scm
+++ b/gnu/packages/gstreamer.scm
@@ -447,9 +447,7 @@ compression formats through the use of the libav library.")
                            (guix build python-build-system))
        #:configure-flags
        (let* ((python (assoc-ref %build-inputs "python"))
-              (python-version ((@@ (guix build python-build-system)
-                                   get-python-version)
-                               python))
+              (python-version (python-version python))
               (python-sitedir (string-append
                                "lib/python" python-version "/site-packages")))
          (list (string-append
diff --git a/gnu/packages/machine-learning.scm b/gnu/packages/machine-learning.scm
index ba7772f66b..e216b9474a 100644
--- a/gnu/packages/machine-learning.scm
+++ b/gnu/packages/machine-learning.scm
@@ -210,8 +210,7 @@ classification.")
              (assoc-ref %standard-phases 'check))
            (add-before 'check 'fix-PYTHONPATH
              (lambda* (#:key inputs outputs #:allow-other-keys)
-               (let ((python-version ((@@ (guix build python-build-system)
-                                           get-python-version)
+               (let ((python-version (python-version
                                       (assoc-ref inputs "python"))))
                  (setenv "PYTHONPATH"
                          (string-append (getenv "PYTHONPATH")
diff --git a/gnu/packages/openldap.scm b/gnu/packages/openldap.scm
index 43f111cf40..2f80920ed4 100644
--- a/gnu/packages/openldap.scm
+++ b/gnu/packages/openldap.scm
@@ -211,7 +211,11 @@ servers from Python programs.")
     (arguments
      `(#:modules ((srfi srfi-1)
                   (guix build gnu-build-system)
+                  ((guix build python-build-system)
+                   #:select (python-version))
                   (guix build utils))
+       #:imported-modules ((guix build python-build-system)
+                           ,@%gnu-build-system-modules)
        #:configure-flags
        (list (string-append "--with-db="
                             (assoc-ref %build-inputs "bdb"))
@@ -263,16 +267,9 @@ servers from Python programs.")
          (add-after 'unpack 'fix-install-location-of-python-tools
            (lambda* (#:key inputs outputs #:allow-other-keys)
              (let* ((out (assoc-ref outputs "out"))
-                    (get-python-version
-                     ;; FIXME: copied from python-build-system
-                     (lambda (python)
-                       (let* ((version     (last (string-split python #\-)))
-                              (components  (string-split version #\.))
-                              (major+minor (take components 2)))
-                         (string-join major+minor "."))))
                     (pythondir (string-append
                                 out "/lib/python"
-                                (get-python-version (assoc-ref inputs "python"))
+                                (python-version (assoc-ref inputs "python"))
                                 "/site-packages/")))
                ;; Install directory must be on PYTHONPATH.
                (setenv "PYTHONPATH"
diff --git a/gnu/packages/package-management.scm b/gnu/packages/package-management.scm
index e1e7d6a5a0..81b3c321e4 100644
--- a/gnu/packages/package-management.scm
+++ b/gnu/packages/package-management.scm
@@ -831,8 +831,7 @@ This package provides Conda as a library.")
              (lambda* (#:key inputs outputs #:allow-other-keys)
                (let* ((out (assoc-ref outputs "out"))
                       (target (string-append out "/lib/python"
-                                             ((@@ (guix build python-build-system)
-                                                  get-python-version)
+                                             (python-version
                                               (assoc-ref inputs "python"))
                                              "/site-packages/")))
                  ;; The installer aborts if the target directory is not on