"""This module contains a code example related to
Think Python, 2nd Edition
by Allen Downey
http://thinkpython2.com
Copyright 2015 Allen Downey
License: http://creativecommons.org/licenses/by/4.0/
"""
from __future__ import print_function, division
class Time:
"""Represents the time of day.
attributes: hour, minute, second
"""
def print_time(t):
"""Prints a string representation of the time.
t: Time object
"""
print('%.2d:%.2d:%.2d' % (t.hour, t.minute, t.second))
def int_to_time(seconds):
"""Makes a new Time object.
seconds: int seconds since midnight.
"""
time = Time()
minutes, time.second = divmod(seconds, 60)
time.hour, time.minute = divmod(minutes, 60)
return time
def time_to_int(time):
"""Computes the number of seconds since midnight.
time: Time object.
"""
minutes = time.hour * 60 + time.minute
seconds = minutes * 60 + time.second
return seconds
def add_times(t1, t2):
"""Adds two time objects.
t1, t2: Time
returns: Time
"""
assert valid_time(t1) and valid_time(t2)
seconds = time_to_int(t1) + time_to_int(t2)
return int_to_time(seconds)
def valid_time(time):
"""Checks whether a Time object satisfies the invariants.
time: Time
returns: boolean
"""
if time.hour < 0 or time.minute < 0 or time.second < 0:
return False
if time.minute >= 60 or time.second >= 60:
return False
return True
def main():
noon_time = Time()
noon_time.hour = 12
noon_time.minute = 0
noon_time.second = 0
print('Starts at', end=' ')
print_time(noon_time)
movie_minutes = 109
run_time = int_to_time(movie_minutes * 60)
print('Run time', end=' ')
print_time(run_time)
end_time = add_times(noon_time, run_time)
print('Ends at', end=' ')
print_time(end_time)
if __name__ == '__main__':
main()
