with open('1.txt','w',encoding='UTF-8') as f:
    f.write('张三,18,男')
    f.close()
with open('1.txt','r',encoding='UTF-8') as f:
    content_list=f.read().splitlines()  
print(content_list)

list=['张三,男,18','李四,男,18','王五,男,18']
with open('2.txt','w',encoding='UTF-8') as f:
    for i in list:
        f.write(i)
        f.write('\n')