在 python>SQLAlchemy 中连接到 mysql (MariaDB) 失败，而在 cmd 中成功

我正在try 使用db_url通过flask应用程序中的一些安全选项连接到远程mysql(MariaDB)数据库.简化测试版本:

from sqlalchemy import create_engine
engine = create_engine(
    'mysql+mysqlconnector://user:password@remote.host.com:3306/mydb?'+
    'ssl_key=/path/to/key.pem'+
    '&ssl_cert=/path/to/scrt.crt'
)
connection = engine.connect()

并获取导致SSL问题的错误

sqlalchemy.exc.InterfaceError: (mysql.connector.errors.InterfaceError) 2026 (HY000): SSL connection error: error:1425F102:SSL routines:ssl_choose_client_version:unsupported protocol
(Background on this error at: http://sqlalche.me/e/rvf5)

(我还try 了pymysql而不是mysqlconnector)

HOWEVER (what I don't understand)

mysql -u user -ppassword mydb -h remote.host.com --ssl-cert=/path/to/scrt.crt --ssl-key=/path/to/key.pem

以防万一:

> SHOW VARIABLES LIKE "%version%";

+-----------------------------------+------------------------------------------+
| Variable_name                     | Value                                    |
+-----------------------------------+------------------------------------------+
| in_predicate_conversion_threshold | 1000                                     |
| innodb_version                    | 10.3.34                                  |
| protocol_version                  | 10                                       |
| slave_type_conversions            |                                          |
| system_versioning_alter_history   | ERROR                                    |
| system_versioning_asof            | DEFAULT                                  |
| version                           | 10.3.34-MariaDB-0ubuntu0.20.04.1         |
| version_comment                   | Ubuntu 20.04                             |
| version_compile_machine           | x86_64                                   |
| version_compile_os                | debian-linux-gnu                         |
| version_malloc_library            | system                                   |
| version_source_revision           | a36fc80aeb3f835fad02f443d65dc608b74b92d1 |
| version_ssl_library               | YaSSL 2.4.4                              |
| wsrep_patch_version               | wsrep_25.24                              |
+-----------------------------------+------------------------------------------+

以防万一2.同样在openssl配置/etc/ssl/openssl.cnf中(服务器1，而不是remote.host.com)

...
[system_default_sect]
MinProtocol = TLSv1.1
...

注意:我最近将服务器更新为Ubuntu 20.04.4 LTS，将python更新为3.8.10(可能与此无关)