docs: Add a python walrus event tracker example (#15)

This is purely a Sui RPC python script that tracks and prints the latest
Walrus related events on Sui.

examples/python/track_walrus_events.py

@@ -0,0 +1,76 @@
+# Track Walrus storage related events on the Sui blockchain
+
+import datetime
+
+# Std lib imports
+import requests
+import re
+
+from utils import num_to_blob_id
+
+PATH_TO_WALRUS_CONFIG = "../CONFIG/config_dir/client_config.yaml"
+
+system_object_id = re.findall(
+    r"system_object:[ ]*(.*)", open(PATH_TO_WALRUS_CONFIG).read()
+)[0]
+print(f"System object ID: {system_object_id}")
+
+# Query the Walrus system object on Sui
+request = {
+    "jsonrpc": "2.0",
+    "id": 1,
+    "method": "sui_getObject",
+    "params": [
+        system_object_id,
+        {
+            "showType": True,
+            "showOwner": False,
+            "showPreviousTransaction": False,
+            "showDisplay": False,
+            "showContent": False,
+            "showBcs": False,
+            "showStorageRebate": False,
+        },
+    ],
+}
+response = requests.post("https://fullnode.testnet.sui.io:443", json=request)
+assert response.status_code == 200
+
+system_object_content = response.json()["result"]["data"]
+walrus_package = re.findall("(0x[0-9a-f]+)::system", system_object_content["type"])[0]
+print(f"Walrus type: {walrus_package}")
+
+# Query events for the appropriate Walrus type
+request = {
+    "jsonrpc": "2.0",
+    "id": 1,
+    "method": "suix_queryEvents",
+    "params": [
+        # Query by module type
+        {"MoveModule": {"package": walrus_package, "module": "blob"}},
+        None,
+        # Query the latest 100 events
+        100,
+        True, # Indicates descending order
+    ],
+}
+response = requests.post("https://fullnode.testnet.sui.io:443", json=request)
+assert response.status_code == 200
+
+events = response.json()["result"]["data"]
+for event in events:
+    # Parse the Walrus event
+    tx_digest = event["id"]["txDigest"]
+    event_type = event["type"][68 + 13 :] # Skip the package & module prefix
+    parsed_event = event["parsedJson"]
+    blob_id = num_to_blob_id(int(parsed_event["blob_id"]))
+    timestamp_ms = int(event["timestampMs"])
+    time_date = datetime.datetime.fromtimestamp(timestamp_ms / 1000.0)
+
+    # For registered blobs get their size in bytes
+    if event_type == "BlobRegistered":
+        size = f"{parsed_event['size']}B"
+    else:
+        size = ""
+
+    print(f"{time_date} {event_type:<15} {size:>10} {blob_id} Tx:{tx_digest:<48}")