When the program is not closed after using the update method, wc.db is occupied and cannot be deleted

[paiguFK]

When I want to delete wocking folder after I have used pysvn's update or other svn related methods
It always prompts that wc.db is occupied and cannot be deleted. Is it possible to manually disconnect the link with the wc.db file?
当我使用了pysvn的update或其他svn相关方法后，想要删除带有.svn的工作文件夹时
总是提示wc.db被占用而不能删除，是否可以手动断开与wc.db文件的链接？
global definition：

调用
def a()
client.update(wc_path)
def del_wc()
shutil.rmtree(father_path, onerror=remove_readonly)

error:
PermissionError: [WinError 32] 另一个程序正在使用此文件，进程无法访问。: 'father_path\wc_path\.svn\wc.db'