MySQL で SQL クエリからカラム名を取得するにはどうすればよいですか?

<code class="python">import MySQLdb

# Connect to MySQL
try:
    db = MySQLdb.connect(host="myhost", user="myuser", passwd="mypass", db="mydb")
except MySQLdb.Error as e:
    print("Error %d: %s" % (e.args[0], e.args[1]))
    sys.exit(1)

# Execute a query
cursor = db.cursor()
cursor.execute("""select ext, sum(size) as totalsize, count(*) as filecount
from fileindex
group by ext
order by totalsize desc;""")

# Get column names
field_names = [i[0] for i in cursor.description]

# Get number of columns
num_fields = len(cursor.description)

# Print column names
print("Column Names:")
for name in field_names:
    print(name)

# Print number of columns
print("Number of Columns:", num_fields)

# Close cursor and db
cursor.close()
db.close()</code>