db = pymysql.connect(...)
cur = db.cursor()
cur.execute(sql)
print(cur.description)
result = cur.fetchall()
data_dict=[]
for field in cur.description:
  data_dict.append(field[0])
print(data_dict)

def __init__(self, connection):
  self.connection = connection
  self.description = None
  self.rownumber = 0
  self.rowcount = -1
  self.arraysize = 1
  self._executed = None
  self._result = None
  self._rows = None
  self._warnings_handled = False