Python获取数组的差异

Question

我有以下两个数组，我试图看看是否元素在无效的\u id \u arr存在在有效的\u id \u arr如果它不存在，那么我会形成差异数组。但是从下面的代码中，我在diff数组['id123', 'id124', 'id125', 'id126', 'id789', 'id666']中看到了以下内容，我希望输出是["id789","id666"]我在这里做错了什么

tag_file= {}
tag_file['invalid_id_arr']=["id123-3431","id124-4341","id125-4341","id126-1w","id789-123","id666"] 
tag_file['valid_id_arr']=["id123-12345","id124-1122","id125-13232","id126-12332","id1new","idagain"] 
diff = [ele.split('-')[0] for ele in tag_file['invalid_id_arr'] if str(ele.split('-')[0]) not in tag_file['valid_id_arr']]

电流输出：

 ['id123', 'id124', 'id125', 'id126', 'id789', 'id666']

预期输出：

 ["id789","id666"]

Answer 1

试试sets：

invalid_id_arr = ["id123-3431","id124-4341","id125-4341","id126-1w","id789-123","id666"] 
valid_id_arr = ["id123-12345","id124-1122","id125-13232","id126-12332","id1new","idagain"] 

set_invalid = set(x.split('-')[0] for x in invalid_id_arr)
print set_invalid.difference(x.split('-')[0] for x in valid_id_arr)

Answer 2

    >>> a = ["id123-3431","id124-4341","id125-4341","id126-1w","id789-123","id666"]
    >>> b = ["id123-12345","id124-1122","id125-13232","id126-12332","id1new","idagain"]
    >>> c = (s.split('-')[0] for s in b)
    >>> [ele.split('-')[0] for ele in a if str(ele.split('-')[0]) not in c]

        ['id789', 'id666']
    >>>  

Answer 3

使用集合更有效，但您的主要问题是没有删除有效的\u id \u arr中的后半部分元素

invalid_id_arr=["id123-3431","id124-4341","id125-4341","id126-1w","id789-123","id666"] 
valid_id_arr=["id123-12345","id124-1122","id125-13232","id126-12332","id1new","idagain"]
valid_id_set = set(ele.split('-')[0] for ele in valid_id_arr)
diff = [ele for ele in invalid_id_arr if ele.split('-')[0] not in valid_id_set]
print diff

输出：

['id789-123', 'id666']

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