Python中的comprehension syntax, conditional expression与 ternary operator
comprehensionsyntax有俩种list,dictconditionalexpression:if在for后面,if修饰整个语句never_login_users=[userforuserinnew_shared_user_idsifis_user_never_login(user)]ternaryoperator:if在for前面,只修饰最前面的usernever_login_use