pymysql.err.InternalError: (1054, "Unknown column 'None' in 'field list'")

Traceback (most recent call last):
  File "D:/projectwc/test/dd.py", line 43, in <module>
    effect_row = cursor.execute("insert into `222` set c={}".format(None))
  File "C:\python\lib\site-packages\pymysql\cursors.py", line 166, in execute
    result = self._query(query)
  File "C:\python\lib\site-packages\pymysql\cursors.py", line 322, in _query
    conn.query(q)
  File "C:\python\lib\site-packages\pymysql\connections.py", line 835, in query
    self._affected_rows = self._read_query_result(unbuffered=unbuffered)
  File "C:\python\lib\site-packages\pymysql\connections.py", line 1019, in _read_query_result
    result.read()
  File "C:\python\lib\site-packages\pymysql\connections.py", line 1302, in read
    first_packet = self.connection._read_packet()
  File "C:\python\lib\site-packages\pymysql\connections.py", line 981, in _read_packet
    packet.check_error()
  File "C:\python\lib\site-packages\pymysql\connections.py", line 393, in check_error
    err.raise_mysql_exception(self._data)
  File "C:\python\lib\site-packages\pymysql\err.py", line 107, in raise_mysql_exception
    raise errorclass(errno, errval)
pymysql.err.InternalError: (1054, "Unknown column ‘None‘ in ‘field list‘")

import pymysql

# 创建连接
conn = pymysql.connect(host=‘192.168.72.135‘, port=3306, user=‘root‘, passwd=‘123456‘, db=‘test‘)
# 创建游标
cursor = conn.cursor()

# 执行SQL，并返回收影响行数
effect_row = cursor.execute("insert into `222` set c={}".format(None))


# 提交，不然无法保存新建或者修改的数据
conn.commit()

# 关闭游标
cursor.close()
# 关闭连接
conn.close()

effect_row = cursor.execute("insert into `222` set c={}".format("Null"))