Command-line tool for OPC UA browsing

Performs OPC UA browse and prints results.
For example:
tools/ls.py opc.tcp://example.org:4840/OpcUa "i=85"

tools/ls.py

+#!/usr/bin/env python
+# lists references of OPC node
+
+import os, sys, argparse, logging
+sys.path.append(os.path.dirname(os.path.realpath(__file__)) + "/..")
+from opcua import ua, Client
+
+FORMATS = ['display-name', 'browse-name', 'node-id']
+
+def main(args, loglevel):
+    logging.basicConfig(format="%(levelname)s: %(message)s", level=loglevel)
+
+    i = -1
+    if args.format in FORMATS:
+        i = FORMATS.index(args.format)
+
+    client = Client(args.address, timeout=10)
+    try:
+        client.connect()
+        if args.node_id:
+            root = client.get_node(ua.NodeId.from_string(args.node_id))
+        else:
+            root = client.get_root_node()
+        for x in root.get_children_descriptions():
+            data = [x.DisplayName.to_string(), x.BrowseName.to_string(), x.NodeId.to_string()]
+            if i >= 0:
+                print(data[i])
+            else:
+                print("\t".join(data))
+    finally:
+        client.disconnect()
+    exit(0)
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description = "Performs OPC UA browse and prints result.")
+    parser.add_argument("address",
+        help = "URL of OPC UA server (for example, opc.tcp://example.org:4840)",
+        metavar = "URL")
+    parser.add_argument("node_id",
+        help = "Fully-qualified node ID (for example, i=85). Default: root node",
+        default='',
+        nargs='?',
+        metavar = "NODE")
+    parser.add_argument(
+        "-v",
+        "--verbose",
+        dest="logLevel",
+        choices=['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'],
+        default='ERROR',
+        help="Set the logging level")
+    parser.add_argument(
+        "-f",
+        "--format",
+        dest="format",
+        choices=['full'] + FORMATS,
+        default='full',
+        help="Set the output format. Default: full")
+    args = parser.parse_args()
+
+    main(args, getattr(logging, args.logLevel))