gnu: Add python-pykwalify.

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

gnu/packages/python-xyz.scm

@@ -16686,3 +16686,28 @@ (define-public python-intelhex
 several convenience Python scripts, including \"classic\" hex2bin and bin2hex
 converters and more, those based on the library itself.")
     (license license:bsd-3)))
+
+(define-public python-pykwalify
+  (package
+    (name "python-pykwalify")
+    (version "1.7.0")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (pypi-uri "pykwalify" version))
+       (sha256
+        (base32
+         "1cnfzkg1b01f825ikpw2fhjclf9c8akxjfrbd1vc22x1lg2kk2vy"))))
+    (build-system python-build-system)
+    (arguments '(#:tests? #f))          ;missing dependencies
+    (propagated-inputs
+     `(("python-dateutil" ,python-dateutil)
+       ("python-docopt" ,python-docopt)
+       ("python-pyyaml" ,python-pyyaml)))
+    (home-page "https://github.com/grokzen/pykwalify")
+    (synopsis
+     "Python lib/cli for JSON/YAML schema validation")
+    (description
+     "This package provides a parser, schema validator, and data binding tool
+for YAML and JSON.")
+    (license license:expat)))