Potential memory leak if not reuse cursor

[chenaoxd]

Describe the bug

conn = connect('clickhouse://localhost')
while True:
    cursor = conn.cursor()
	cursor.close()

There will be a memory leak here because of this line of code:

clickhouse-driver/clickhouse_driver/dbapi/connection.py

Line 92 in 0d607df

self.cursors.append(cursor)

To Reproduce

Run the code above

Expected behavior

cursor should be garbage collected, but it can't be because of this line of code:

clickhouse-driver/clickhouse_driver/dbapi/connection.py

Line 92 in 0d607df

self.cursors.append(cursor)

Versions

• clickhouse-driver==0.2.0
• Python version: 3.7.5