[PATCH 02/12] guix: Add a "pypi-uri" helper method.

[Cyril Roelandt]

* guix/download.scm (mirrors): New "pypi" mirror.
* guix/build-system/python.scm (pypi-uri): New method.
---
 guix/build-system/python.scm | 10 +++++++++-
 guix/download.scm            |  4 +++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/guix/build-system/python.scm b/guix/build-system/python.scm
index e9fffcc..01525f4 100644
--- a/guix/build-system/python.scm
+++ b/guix/build-system/python.scm
@@ -31,7 +31,8 @@
   #:export (%python-build-system-modules
             package-with-python2
             python-build
-            python-build-system))
+            python-build-system
+            pypi-uri))
 
 ;; Commentary:
 ;;
@@ -40,6 +41,13 @@
 ;;
 ;; Code:
 
+(define (pypi-uri name version)
+  "Return a URI string for the Python package hosted on the Python Package
+Index (PyPI) corresponding to NAME and VERSION."
+  (string-append "mirror://pypi/packages/source/"
+                 (string-take name 1) "/" name "/"
+                 name "-" version ".tar.gz"))
+
 (define %python-build-system-modules
   ;; Build-side modules imported by default.
   `((guix build python-build-system)
diff --git a/guix/download.scm b/guix/download.scm
index 8ec47ce..53b28be 100644
--- a/guix/download.scm
+++ b/guix/download.scm
@@ -200,7 +200,9 @@
       (debian
        "http://ftp.de.debian.org/debian/";
        "http://ftp.fr.debian.org/debian/";
-       "http://ftp.debian.org/debian/";))))
+       "http://ftp.debian.org/debian/";)
+      (pypi
+       "https://pypi.python.org/";))))
 
 (define %mirror-file
   ;; Copy of the list of mirrors to a file.  This allows us to keep a single
-- 
2.1.4