<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _scope_vars(scope, trainable_only=False):
 """ Get variables inside a scope The scope can be specified as a string Parameters scope: str or VariableScope scope in which the variables reside. trainable_only: bool whether or not to return only the variables that were marked as trainable. Returns ------- vars: [tf.Variable] list of variables in `scope`. """

    return tf.get_collection(
        tf.GraphKeys.TRAINABLE_VARIABLES
        if trainable_only else tf.GraphKeys.VARIABLES,
        scope=scope if isinstance(scope, str) else scope.name)