Have an example program too.

Signed-off-by: Flynn <emissary@flynn.kodachi.com>

examples/gep2257.py

@@ -0,0 +1,39 @@
+#!/usr/bin/python3
+# -*- coding:utf-8 -*-
+
+"""
+This example uses kubernetes.utils.duration to parse and display
+a GEP-2257 duration string (you can find the full specification at
+https://gateway-api.sigs.k8s.io/geps/gep-2257/).
+
+Good things to try:
+>>> python examples/gep2257.py 1h
+Duration: 1h
+>>> python examples/gep2257.py 3600s
+Duration: 1h
+>>> python examples/gep2257.py 90m
+Duration: 1h30m
+>>> python examples/gep2257.py 30m1h10s5s
+Duration: 1h30m15s
+>>> python examples/gep2257.py 0h0m0s0ms
+Duration: 0s
+>>> python examples/gep2257.py -5m
+ValueError: Invalid duration format: -5m
+>>> python examples/gep2257.py 1.5h
+ValueError: Invalid duration format: 1.5h
+"""
+
+import sys
+
+from kubernetes.utils import duration
+
+def main():
+    if len(sys.argv) != 2:
+        print("Usage: {} <duration>".format(sys.argv[0]))
+        sys.exit(1)
+
+    dur = duration.parse_duration(sys.argv[1])
+    print("Duration: %s" % duration.format_duration(dur))
+
+if __name__ == "__main__":
+    main()