A = range(1,10)
B = range(5,15)
C =range(8,20)
# A并B并c
result2 = list(set(A).intersection(set(B)).intersection(set(C)))
print(result2)
# AUBUC 并集
result3 = list(set(A).union(set(B).union(C)))
print(result3)
# 差集
# 元素在 A not B
result4 = list(set(A).difference(set(B)))
print(result4)