# 生成器表达式,生成可迭代对象,不能反复迭代(延迟求值,惰性求值)tmp = (x for x in range(9))print(type(tmp))print(next(tmp)) # 结果:0print(next(tmp)) # 结果:1for i in tmp: # 循环迭代不容易出现边界错误 print(i)