Comparing two sets in python

2019-09-02 07:04发布

Hi guys,i have a doubt regarding comparing two sets

    >>> x = {"a","b","1","2","3"}  
    >>> y = {"c","d","f","2","3","4"}  
    >>> z=x<y        
    >>> print(z)
    False
    >>> z=x>y
    >>> print(z)
    False

In the above logic,for both z=x<y and z=x>y. I'm getting output as False,whereas one of the expression should return True. Could anyone explain me why?

标签: python set
3条回答
在下西门庆
2楼-- · 2019-09-02 07:19

The < and > operators are testing for strict subsets. Neither of those sets is a subset of the other.

{1, 2} < {1, 2, 3}  # True
{1, 2} < {1, 3}  # False
{1, 2} < {1, 2}  # False -- not a *strict* subset
{1, 2} <= {1, 2}  # True -- is a subset
查看更多
Root(大扎)
3楼-- · 2019-09-02 07:32

When working with sets, > and < are relational operators. hence, these operations are used to see if one set is the proper subset of the other, which is False for as neither is the proper subset of the other.

查看更多
你好瞎i
4楼-- · 2019-09-02 07:40

Straight from the python documentation --

In addition, both Set and ImmutableSet support set to set comparisons. Two sets are equal if and only if every element of each set is contained in the other (each is a subset of the other). A set is less than another set if and only if the first set is a proper subset of the second set (is a subset, but is not equal). A set is greater than another set if and only if the first set is a proper superset of the second set (is a superset, but is not equal).

查看更多
登录 后发表回答