Changed type engine approach following the advice given by:
Changed type engine approach following the advice given by:

https://github.com/zzzeek/sqlalchemy/blob/master/lib/sqlalchemy/dialects/type_migration_guidelines.txt

Each snowflake-specific timestamp type -- _tz, _ntz, and _ltz -- is
now its own type subclassing sqltypes.TIMESTAMP; and the type compiler
has visit_* methods for all three types, which add keyword arguments to
influence the behavior of visit_TIMESTAMP.

snowflakedb/snowflake-sqlalchemy,snowflakedb/snowflake-sqlalchemy