知识要点 list.format ()
一个是list.format的使用, 还有一个iter的调用.
urls = ['www.baidu.com/page/{}'.format(str(s)) for s in range(30,90,30)]
a = iter(urls)
print(urls)
print(a)
b= next(a)
print(b)
print("------------------")
print(next(a))
' ' '
#结果:
# ['www.baidu.com/page/30', 'www.baidu.com/page/60']
# <list_iterator object at 0x00000000026E7A20>
# www.baidu.com/page/30
# ------------------
# www.baidu.com/page/60