def _engine_builder(con):
global _SQLALCHEMY_INSTALLED<EOL>if isinstance(con, str):<EOL><INDENT>try:<EOL><INDENT>import sqlalchemy<EOL><DEDENT>except ImportError:<EOL><INDENT>_SQLALCHEMY_INSTALLED = False<EOL><DEDENT>else:<EOL><INDENT>con = sqlalchemy.create_engine(con)<EOL>return con<EOL><DEDENT><DEDENT>return con<EOL>
Returns a SQLAlchemy engine from a URI (if con is a string)
else it just return con without modifying it.