gnu: Add python-czml3.

* gnu/packages/astronomy.scm (python-czml3): New variable.

Signed-off-by: Nicolas Goaziou <mail@nicolasgoaziou.fr>

gnu/packages/astronomy.scm

@@ -1281,6 +1281,37 @@ attempting to maintain ISTP compliance
 @end itemize")
     (license license:expat)))
 
+(define-public python-czml3
+  (package
+    (name "python-czml3")
+    (version "0.7.0")
+    (source (origin
+              (method git-fetch)
+              (uri (git-reference
+                    (url "https://github.com/poliastro/czml3")
+                    (commit (string-append "v" version))))
+              (file-name (git-file-name name version))
+              (sha256
+               (base32
+                "0pbwcsmc9nw591rck586ca9hwwhmm54rjjmp8gflhzq8b7f48lkc"))))
+    (build-system pyproject-build-system)
+    (propagated-inputs
+     (list python-attrs
+           python-dateutil
+           python-w3lib))
+    (native-inputs
+     (list python-astropy
+           python-pytest
+           python-pytest-cov
+           python-pytest-mypy))
+    (home-page "https://github.com/poliastro/czml3")
+    (synopsis "Python library to write CZML")
+    (description
+     "CZML3 is a Python library to write CZML, a JSON format for describing
+a time-dynamic graphical scene, primarily for display in a web browser running
+Cesium.")
+    (license license:expat)))
+
 (define-public python-drms
   (package
     (name "python-drms")