file = open("test.txt","r")
content = file.read()
conlist=list(content)
conlist.sort()#.sort()直接排序,本身是没有返回值的,print(xx.sort() )的结果是 None
file.close()
print("".join(conlist))# join() 方法可以将列表链接为字符串
file = open("test.txt","r")
content = file.read()
conlist=list(content)
conlist.sort()#.sort()直接排序,本身是没有返回值的,print(xx.sort() )的结果是 None
file.close()
print("".join(conlist))# join() 方法可以将列表链接为字符串