gnu: Add python-cyclic.

* gnu/packages/python-xyz.scm (python-cyclic): New variable.

gnu/packages/python-xyz.scm

@@ -30379,3 +30379,26 @@ window managers.")
      "Script for Sway and i3 to automatically switch the horizontal/vertical
  window split orientation.")
     (license license:gpl3)))
+
+(define-public python-cyclic
+  (package
+    (name "python-cyclic")
+    (version "1.0.0")
+    (source (origin
+              ;; Use git, as there are some test files missing from the PyPI
+              ;; release, see https://github.com/neurobin/cyclic/issues/1
+              (method git-fetch)
+              (uri (git-reference
+                    (url "https://github.com/neurobin/cyclic")
+                    ;; Release is not tagged on github, see
+                    ;; https://github.com/neurobin/cyclic/issues/2
+                    (commit "bf616c47ea49a43500ea55a1e6f4890323be0679")))
+              (file-name (git-file-name name version))
+              (sha256
+               (base32
+                "0r8zzjdv70fpxssxps62rlgpii8fr9gh8gykdygqn6mkdnfjwgjc"))))
+    (build-system python-build-system)
+    (home-page "https://github.com/neurobin/cyclic")
+    (synopsis "Handle cyclic relations")
+    (description "This package handles cyclic relations compared by value.")
+    (license license:bsd-3)))