你的函数prime有问题,它的返回值应该是布尔类型
下面是一种可能的答案
fo = open("PY1403.txt","w")
def prime(num):
for i in range(2,int(num**0.5)+1):
if num%i == 0:
return False
return True
ls = [...]#此处我就省略了
ls_new = []
for i in ls:
if prime(i) == False:
ls_new.append(i)
fo.write(">>>{},列表长度为{}".format(ls_new,len(ls_new)))
fo.close()