Python 3 - Working with datetime.time objects - timedelta

Question

Just got a problem I don't understand in my python code.

timestamps = list(map(lambda ts: ts.time, timestamps))
start_timestamps = timestamps
end_timestamps = timestamps[1:]
d = date(2000, 1, 1)
FMT = '%H:%M:%S'
for i, t1 in enumerate(start_timestamps):
    t1 = datetime.combine(d, start_timestamps[i])
    t2 = datetime.combine(d, end_timestamps[i])
    dt = t1 - t2
    #dt = datetime.strptime(t1,FMT) - datetime.strptime(t2,FMT)

By using this in my django project I get the following error:

t2 = datetime.combine(d, end_timestamps[i])

TypeError: combine() argument 2 must be datetime.time, not bytes

When uncommenting the last line und commenting the three lines above it, I'm getting the following:

dt = datetime.strptime(t1,FMT) - datetime.strptime(t2,FMT)

TypeError: must be str, not datetime.time

So I really don't understand it. It is datetime.time , but the same time it is not ... Can anyone help me?

Thanks!

Answer 1

Some of your objects are bytes objects, and others are datetime.time objects. In other words, you have a mix of objects.

Note that it was end_timestamps[i] that failed, not start_timestamps[i] , in your first error. Ergo, start_timestamps[i] was a time object. If all objects in timestamps where bytes objects, datetime.combine(d, start_timestamps[i]) would have failed.

You need to figure out why your ts.time() calls in your map() call return inconsistent data types.