%格式化
　　print('%2d-%02d-%.2f' % (3, 1, 2.113))
　　输出 ：' 3-01-2.11'

format()格式化
　　print("{0:2d}-{1:02d}-{2:.2f}-{3:0<4d}".format(1, 5, 6, 7))
　　输出：' 1-05-6.00-7000'
　　
　　print("{0}{1:0>2d}{2:0>2d}{3:0>2d}".format(*time.localtime()))

f-sting()
   r=2.5
   s=3.14*r
　　print(f'The area of a circle with radius {r} is {s:.2f}')
　　输入：The area of a circle with radius 2.5 is 19.62