Provide examples for python podman API

Signed-off-by: Jhon Honce <jhonce@redhat.com>

Closes: #870
Approved by: rhatdan

contrib/python/examples/eg_new_image.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+"""Example: Create new image from container."""
+
+import sys
+
+import podman
+
+
+def print_history(details):
+    """Format history data from an image, in a table."""
+    for i, r in enumerate(details):
+        print(
+            '{}: {} {} {}'.format(i, r.id[:12],
+                                  podman.datetime_format(r.created), r.tags),
+            sep='\n')
+    print("-" * 25)
+
+
+print('{}\n'.format(__doc__))
+
+with podman.Client() as client:
+    ctnr = next(
+        (c for c in client.containers.list() if 'alpine' in c['image']), None)
+
+    if ctnr:
+        print_history(client.images.get(ctnr.imageid).history())
+
+        # Make changes as we save the container to a new image
+        id = ctnr.commit('alpine-ash', changes=['CMD=/bin/ash'])
+        print_history(client.images.get(id).history())
+    else:
+        print('Unable to find "alpine" container.', file=sys.stderr)