python 集合关系运算交，差 day14

Posted 2020-11-20 wangleiyifan

去重并创建集合（无序）

python_1 = [‘1‘,‘2‘,‘3‘]
linux_1 = [‘1‘,‘2‘]
#python_and_linux_1 = []
#for p_name in python_1:
#    if p_name in linux_1:
#        python_and_linux_1.append(p_name)
#print(python_and_linux_1)
p_s = set(python_1)
print(p_s)

求交集

python_1 = [‘1‘,‘2‘,‘3‘]
linux_1 = [‘1‘,‘2‘]
#python_and_linux_1 = []
#for p_name in python_1:
#    if p_name in linux_1:
#        python_and_linux_1.append(p_name)
#print(python_and_linux_1)
p_s = set(python_1)
l_s = set(linux_1)
print(p_s,l_s)
print(p_s.intersection(l_s))
print(p_s&l_s)#同上述函数

求并集

python_1 = [‘1‘,‘2‘,‘3‘]
linux_1 = [‘1‘,‘2‘,‘4‘]
#python_and_linux_1 = []
#for p_name in python_1:
#    if p_name in linux_1:
#        python_and_linux_1.append(p_name)
#print(python_and_linux_1)
p_s = set(python_1)
l_s = set(linux_1)
print(p_s,l_s)
print(p_s.union(l_s))
print(p_s|l_s)

求差集

python_1 = [‘1‘,‘2‘,‘3‘]
linux_1 = [‘1‘,‘2‘,‘4‘]
#python_and_linux_1 = []
#for p_name in python_1:
#    if p_name in linux_1:
#        python_and_linux_1.append(p_name)
#print(python_and_linux_1)
p_s = set(python_1)
l_s = set(linux_1)
print(p_s,l_s)

print(p_s.difference(l_s))

print(p_s-l_s)

 

 

集合其他方法

交叉补集   并集-交集

python_1 = [‘1‘,‘2‘,‘3‘]
linux_1 = [‘1‘,‘2‘,‘4‘]
#python_and_linux_1 = []
#for p_name in python_1:
#    if p_name in linux_1:
#        python_and_linux_1.append(p_name)
#print(python_and_linux_1)
p_s = set(python_1)
l_s = set(linux_1)
print(p_s,l_s)
print(p_s.symmetric_difference(l_s))
print(p_s^l_s)

difference_update 

p_s=p_s-l_s

==p_s.difference_update(l_s)

同理 intersection_update

 

isdisjoint   两个合集无共同元素

返回布尔值

issubset，s1包含于s2，子集

相当于s1<s2

返回布尔值

python_1 = [‘1‘,‘2‘,‘3‘]
linux_1 = [‘1‘,‘2‘,‘4‘]
p_s = set(python_1)
l_s = set(linux_1)
print(p_s,l_s)
print(p_s.issubset(l_s))

issuperset，父集

 

update更新元素，add只能添加一个元素

s1={1,2}
s2={1,2,3,4}
s1.update(s2)
print(s1)