these thread can help: https://mail.python.org/archives/list/kwant-discuss@python.org/thread/KZXFIC4N6GOD6IQ7WZYEHPCUEKGRCL5V/#5WUA27JKU6OUEWNTWKDZZW5BXB6RSV2R https://mail.python.org/archives/list/kwant-discuss@python.org/thread/YYOG27S6PAIBI3G2T5OQGKTVCE6G7D2X/#YYOG27S6PAIBI3G2T5OQGKTVCE6G7D2X
Best, Diego