Python3.x：格式浮动到2位，限制为3个小数位

Question

I have seen many questions about formatting floats and limiting decimal places, but I have not seen both done at once. I want the values for my variable seconds to always be represented as SS.mmm.

I have

t = int(input('time?: '))
seconds = (t / 1000) % 60
minutes = (t // (1000 * 60)) % 60
hours = (t // (1000 * 60 * 60)) % 24

I want to print hours , minutes , and seconds so that it will always follow HH:MM:SS.mmm

My attempt:

print('{}:{}:{}'.format("%02d" % hours, "%02d" % minutes, ("%.3f" % seconds).zfill(2)))

I end up getting HH:MM:S.mmm sometimes. I need there to be two seconds digits even if there is a leading zero.

Answer 1

You should be able to do the following with .format() :

print('{:0>2d}:{:0>2d}:{:06.3f}'.format(hours,minutes,seconds))

In particular, 0>2d forces the integers hours and minutes to be of length 2. Further, 06.3f implies that the entire float representation should be 6 characters long (including the '.' ) and have 3 decimal places to the right of the period.