gnu: Add python-pyzx.

* gnu/packages/python-science.scm (python-pyzx): New variable.

Change-Id: I69895a9deb5739db9c0d5e793e3f864c800f4504
Reviewed-by: @lilyp
Signed-off-by: Sharlatan Hellseher <sharlatanus@gmail.com>

gnu/packages/python-science.scm

@@ -29,6 +29,7 @@
 ;;; Copyright © 2024 Nicolas Graves <ngraves@ngraves.fr>
 ;;; Copyright © 2024 Rick Huijzer <ikbenrickhuyzer@gmail.com>
 ;;; Copyright © 2025 Nicolas Graves <ngraves@ngraves.fr>
+;;; Copyright © 2025 Mark Walker <mark.damon.walker@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -553,6 +554,58 @@ allows arithmetic operations between them and conversions from and to
 different units.")
     (license license:bsd-3)))
 
+(define-public python-pyzx
+  (package
+    (name "python-pyzx")
+    (version "0.9.0")
+    (source
+     (origin
+       (method git-fetch)        ; no tests in PyPI
+       (uri (git-reference
+             (url "https://github.com/zxcalc/pyzx")
+             (commit (string-append "v" version))))
+       (file-name (git-file-name name version))
+       (sha256
+         (base32 "1bnmz08w1bmipir1wnn1k3fw64rply7891xns22qfj6yh0j1n6rj"))))
+    (build-system pyproject-build-system)
+    (arguments (list #:test-flags
+                     #~(list
+                        ;; Ignore long running tests
+                        "--ignore=tests/long_test.py"
+                        "--ignore=tests/long_scalar_test.py")
+                     #:phases
+                     #~(modify-phases %standard-phases
+                         (add-before 'check 'pre-check
+                           (lambda* (#:key inputs outputs #:allow-other-keys)
+                             (setenv "HOME" "/tmp")
+                             ;; Matplotlib needs to be able to write its
+                             ;; configuration file somewhere.
+                             (setenv "MPLCONFIGDIR" "/tmp"))))))
+    (native-inputs (list python-pytest
+                         python-setuptools
+                         python-wheel))
+    (propagated-inputs (list python-ipywidgets
+                             python-lark
+                             python-numpy
+                             python-pyperclip
+                             python-tqdm))
+    (home-page "https://github.com/zxcalc/pyzx")
+    (synopsis "Quantum circuit rewriting and optimisation using the ZX-calculus")
+    (description
+     "PyZX is a Python tool implementing the theory of ZX-calculus for the
+creation, visualisation, and automated rewriting of large-scale quantum
+circuits.  PyZX currently allows you to:
+
+@itemize
+@item Read in quantum circuits in the file format of QASM, Quipper or Quantomatic;
+@item Rewrite circuits into a pseudo-normal form using the ZX-calculus;
+@item Extract new simplified circuits from these reduced graphs;
+@item Visualise the ZX-graphs and rewrites using either Matplotlib, Quantomatic
+or as a TikZ file for use in LaTeX documents;
+@item Output the optimised circuits in QASM, QC or QUIPPER format.
+@end itemize")
+    (license license:asl2.0)))
+
 (define-public python-qdldl
   (package
     (name "python-qdldl")