在Python中,计算两个列表之间的差值的最佳方法是什么?
例子
A = [1,2,3,4]
B = [2,5]
A - B = [1,3,4]
B - A = [5]
在Python中,计算两个列表之间的差值的最佳方法是什么?
例子
A = [1,2,3,4]
B = [2,5]
A - B = [1,3,4]
B - A = [5]
当前回答
一个衬套:
diff = lambda l1,l2: [x for x in l1 if x not in l2]
diff(A,B)
diff(B,A)
Or:
diff = lambda l1,l2: filter(lambda x: x not in l2, l1)
diff(A,B)
diff(B,A)
其他回答
你可以做一个
list(set(A)-set(B))
and
list(set(B)-set(A))
如果顺序无关紧要,你可以简单地计算集合差值:
>>> set([1,2,3,4]) - set([2,5])
set([1, 4, 3])
>>> set([2,5]) - set([1,2,3,4])
set([5])
如果你不关心项目的顺序或重复,请使用set。使用列表推导式:
>>> def diff(first, second):
second = set(second)
return [item for item in first if item not in second]
>>> diff(A, B)
[1, 3, 4]
>>> diff(B, A)
[5]
>>>
一个衬套:
diff = lambda l1,l2: [x for x in l1 if x not in l2]
diff(A,B)
diff(B,A)
Or:
diff = lambda l1,l2: filter(lambda x: x not in l2, l1)
diff(A,B)
diff(B,A)
在字典列表的情况下,当集合解引发时,完整列表理解解工作
TypeError: unhashable type: 'dict'
测试用例
def diff(a, b):
return [aa for aa in a if aa not in b]
d1 = {"a":1, "b":1}
d2 = {"a":2, "b":2}
d3 = {"a":3, "b":3}
>>> diff([d1, d2, d3], [d2, d3])
[{'a': 1, 'b': 1}]
>>> diff([d1, d2, d3], [d1])
[{'a': 2, 'b': 2}, {'a': 3, 'b': 3}]