pymysql,Lost connection to MySQL server during que

Question

Lost connection to MySQL server during query, how can I fix this? Better fix this in my program.

import pymysql
connection = pymysql.connect(host='***',
                                 user='***',
                                 password='***',
                                 db='***',
                                 charset='utf8mb4',
                                 cursorclass=pymysql.cursors.DictCursor
                                 )

with connection.cursor() as cursor:
    sql = "SELECT MAX(group_id) FROM topic_duplicate_check"
    cursor.execute(sql) # Exception
    r = cursor.fetchone()
    max_gid = None
    try:
        max_gid = r['MAX(group_id)']
    except:
        pass
    print(max_gid)

C:\ProgramData\Anaconda3\python.exe F:/group_topics/main.py Traceback (most recent call last): File "F:/group_topics/main.py", line 41, in cursor.execute(sql) File "C:\ProgramData\Anaconda3\lib\site-packages\pymysql\cursors.py", line 166, in execute result = self._query(query) File "C:\ProgramData\Anaconda3\lib\site-packages\pymysql\cursors.py", line 322, in _query conn.query(q) File "C:\ProgramData\Anaconda3\lib\site-packages\pymysql\connections.py", line 856, in query self._affected_rows = self._read_query_result(unbuffered=unbuffered) File "C:\ProgramData\Anaconda3\lib\site-packages\pymysql\connections.py", line 1057, in _read_query_result result.read() File "C:\ProgramData\Anaconda3\lib\site-packages\pymysql\connections.py", line 1340, in read first_packet = self.connection._read_packet() File "C:\ProgramData\Anaconda3\lib\site-packages\pymysql\connections.py", line 987, in _read_packet packet_header = self._read_bytes(4) File "C:\ProgramData\Anaconda3\lib\site-packages\pymysql\connections.py", line 1033, in _read_bytes CR.CR_SERVER_LOST, "Lost connection to MySQL server during query") pymysql.err.OperationalError: (2013, 'Lost connection to MySQL server during query')

Process finished with exit code 1