Question

我正在编写一个程序，以在两个时间范围（小时，分钟）之间打印一定范围的时隙（小时，分钟对）。运行此程序时，我看到意外的输出：

import datetime,time
def stamp(hour, min):
    return int(datetime.datetime(2018, 7, 17, hour,min).timestamp())
def ListSlotsAvailable(start, ent, durn):
    secdurn=durn*60
    for sec in range(start, ent, secdurn):
        enttime = sec+secdurn
        print("Stamp is %d-%d" % (sec, enttime))
        print(hour_from_stamp(sec))
        print(min_from_stamp(sec))
        print(hour_from_stamp(enttime))
        print(min_from_stamp(enttime))
def hour_from_stamp(stamp):
    import datetime
    print(datetime.datetime.fromtimestamp(stamp).strftime('%H'))

def min_from_stamp(stamp):
    import datetime
    print(datetime.datetime.fromtimestamp(stamp).strftime('%M'))

starthr=input("Give start time in hour")
startmin=input("Give start time in min")
start=stamp(int(starthr), int(startmin))
endhr=input("Give end time in hour")
endmin=input("Give end time in min")
ent=stamp(int(endhr), int(endmin))
durn=int(input("Give duration for each consultation"))
ListSlotsAvailable(start, ent, durn)

输出：

Give start time in hour10
Give start time in min15
Give end time in hour12
Give end time in min30
Give duration for each consultation30
Stamp is 1531802700-1531804500
10
None
15
None
10
None
45
None
Stamp is 1531804500-1531806300
10
None
45
None
11
None
15
None
Stamp is 1531806300-1531808100
11
None
15
None
11
None
45
None
Stamp is 1531808100-1531809900
11
None
45
None
12
None
15
None
Stamp is 1531809900-1531811700
12
None
15
None
12
None
45
None

1

我没想到在那里看到None值。他们来自哪里？

Answer 1

您的函数应该返回这些字符串值，而不是打印：

def hour_from_stamp(stamp):
    import datetime
    return datetime.datetime.fromtimestamp(stamp).strftime('%H')

def min_from_stamp(stamp):
    import datetime
    print datetime.datetime.fromtimestamp(stamp).strftime('%M')

否则，没有显式返回值的函数将默认返回None。

时间范围之间的意外输出写列表时隙

1 个答案: