Bip39 dart https://www.demilked.com/author/gobnettlmz/ Regardless that it makes use of BIP32 system you may continue to import BIP39 seeds into Electrum wallet. Also aside from BIp32 You can find BIP44 version which some wallet use to the era of seeds. Push X to abort passphrase software and maintain modifying the passphrase. https://squareblogs.net/edelinepge/using-python-to-produce-a-bip39-mnemonic-a-developers-point-of-view