Python实现比较两个列表(list)范围

有一道题： 比较两个列表范围，如果包含的话，返回TRUE，否则FALSE。 详细题目如下：

Create a function, this function receives two lists as parameters, each list indicates a scope of numbers, the function judges whether list2 is included in list1.

Function signature:
    differ_scope(list1, list2)

Parameters:
    list1, list2    - list1 and list2 are constructed with strings,
                      each string indicates a number or a scope of
                      numbers. The number or scope are randomly, can
                      be overlapped. All numbers are positive.

E.g.
                            ['23', '44-67', '12', '3', '20-90']
 Return Values:
    True            - if all scopes and numbers indicated by list2 are included in list1.
    False           - if any scope or number in list2 is out of the range in list1.
 Examples:
    case1    - list1 = ['23', '44-67', '12', '3', '20-90']
               list2 = ['22-34', '33', 45', '60-61']
               differ_scope(list1, list2) == True
    case2    - list1 = ['23', '44-67', '12', '3', '20-90']
               list2 = ['22-34', '33', 45', '60-61', '100']
               differ_scope(list1, list2) == False

贴上自己写的代码如下:(备注： python 2.7.6)