docs: document for python example

docs/examples/python/highvolume_example.py

 import logging
 import sys
-import threading
 import time
 from multiprocessing import Queue, Process
 from queue import Empty
+from typing import List
 
 import taos
 from taos import TaosConnection
-from typing import List
 
 logging.basicConfig(stream=sys.stdout, level=logging.DEBUG, format="%(asctime)s [%(name)s] - %(message)s")
 
@@ -25,6 +24,7 @@ def get_connection():
     return taos.connect(host="localhost", user="root", password="taosdata", port=6030)
 
 
+# ANCHOR: DataBaseMonitor
 class DataBaseMonitor:
     def __init__(self):
         self.conn: TaosConnection = get_connection()
@@ -55,10 +55,13 @@ class DataBaseMonitor:
                 logging.info(f"count={count} speed={(count - last_count) / 10}")
                 last_count = count
         except KeyboardInterrupt:
-            [p.kill() for p in read_processes]
-            [p.kill for p in write_processes]
+            [p.terminate() for p in read_processes]
+            [p.terminate() for p in write_processes]
+
 
+# ANCHOR_END: DataBaseMonitor
 
+# ANCHOR: MockDataSource
 class MockDataSource:
     location = ["LosAngeles", "SanDiego", "Hollywood", "Compton", "San Francisco"]
     current = [8.8, 10.7, 9.9, 8.9, 9.4]
@@ -91,6 +94,9 @@ class MockDataSource:
             raise StopIteration
 
 
+# ANCHOR_END: MockDataSource
+
+# ANCHOR: SQLWriter
 class SQLWriter:
     log = logging.getLogger("SQLWriter")
 
@@ -170,19 +176,21 @@ class SQLWriter:
         return self._buffered_count
 
 
-def run_read_task(task_id: int, task_queues: List[Queue]):
-    log = logging.getLogger(f"ReadTask-{task_id}")
+# ANCHOR_END: SQLWriter
 
+# ANCHOR: read
+def run_read_task(task_id: int, task_queues: List[Queue]):
     table_count_per_task = TABLE_COUNT // READ_TASK_COUNT
     data_source = MockDataSource(f"tb{task_id}", table_count_per_task)
-    try:
-        for table_id, line in data_source:
-            i = table_id % len(task_queues)
-            task_queues[i].put(line, block=True)
-    except KeyboardInterrupt:
-        pass
+    for table_id, line in data_source:
+        i = table_id % len(task_queues)
+        task_queues[i].put(line, block=True)
+
+
+# ANCHOR_END: read
 
 
+# ANCHOR: write
 def run_write_task(task_id: int, queue: Queue):
     log = logging.getLogger(f"WriteTask-{task_id}")
     writer = SQLWriter()
@@ -196,14 +204,14 @@ def run_write_task(task_id: int, queue: Queue):
                     writer.flush()
                 else:
                     time.sleep(0.01)
-    except KeyboardInterrupt:
-        pass
     except BaseException as e:
         msg = f"line={line}, buffer_count={writer.buffered_count}"
         log.debug(msg)
         raise e
 
 
+# ANCHOR_END: write
+
 def set_global_config():
     argc = len(sys.argv)
     if argc > 1:
@@ -220,6 +228,7 @@ def set_global_config():
         MAX_BATCH_SIZE = sys.argv[4]
 
 
+# ANCHOR: main
 def main():
     set_global_config()
     logging.info(f"READ_TASK_COUNT={READ_TASK_COUNT}, WRITE_TASK_COUNT={WRITE_TASK_COUNT}, TABLE_COUNT={TABLE_COUNT}, MAX_BATCH_SIZE={MAX_BATCH_SIZE}")
@@ -248,5 +257,7 @@ def main():
     database_monitor.stat_and_print()
 
 
+# ANCHOR_END: main
+
 if __name__ == '__main__':
     main()