使用python比较两个数组，获取交集和并集

print('=============')


def readT(filename):
    arr = ''
    print('====================')
    with open(filename,'r') as f_r:
       lines = f_r.readline()
       arr = lines.split(' ')
    return arr

line_os = readT('lh.txt')

line_ts = readT('sh.txt')

#
#print(set(line_os) & set(line_ts))

#
lines = set(line_os) | set(line_ts)

print(lines)

line_txt = ' '.join(lines)

print(line_txt)

with open('pos.txt','w',encoding='utf-8') as f_w:
     f_w.write(line_txt)
     f_w.close()

#print(line_os)
#print('==================')
#print(line_ts)

扩展知识：

print set(a) & set(b) # 交集, 等价于set(a).intersection(set(b))
print set(a) | set(b) # 并集, 等价于set(a).union(set(b))
print set(a) - set(b) # 差集，在a中但不在b中的元素, 等价于set(a).difference(set(b))
print set(b) - set(a) # 差集，在b中但不在a中的元素, 等价于set(b).difference(set(a))