Python---set

'''help---set, 
1. no sequencial, random
2. no repeated value
'''
my_set={1,'data1',2,'value'}
print(my_set)
a_list = [1,2,3]
tt_set=set(a_list)
print(tt_set)
print(len(my_set))
my_set.add('33333')
print(my_set)
my_set.update({1,'data1',33})
print(my_set)
my_set.update([6,7,'8'])
print(my_set)
my_set.update([11],{22})
print(my_set)
my_set.discard(11)
'''will not have exception'''
print(my_set)
my_set.remove(22)
'''if not exist, will raise exception'''
print(my_set)
print(my_set.pop())
print(my_set)
my_set.clear()
print(my_set)

set1={1,2,3}
set2={1,3,5}
print(set1.union(set2))
print(set1.intersection(set2))
print(set1.difference(set2))
print(set1.symmetric_difference(set2))
set3={1,2,3,5}
print(set1.issubset(set3))
print(set3.issuperset(set1))

set4=set()
if set4:
    print('True')
else:
    print('False')