I'm trying to read a time currently represented as a string into a Django TimeField Model in Python 2.7 and scale it via a float at the same time.
For example:
00:31:14 / 1.0617 = 00:29:20
I've successfully read in the time and stored into the model but can't scale the time in a "nice" way (currently I read the time object back out of the database and update it).
I would like to use the python datatime object that the TimeField is based on to do this calculation before saving to the database.
Relevant code:
class Time(models.Model):
time = models.TimeField()
date = models.DateField()
date = "12/6/2009"
time = "00:31:14"
date = datetime.strptime(date, "%d/%m/%Y").strftime("%Y-%m-%d")
time = models.Time(date=date, time=time)
time.save()
db_instance = models.Time.objects.all().filter(id=time.id)[0]
db_instance.time = db_instance.time.replace(
minute=int((db_instance.time.minute * 60 + db_instance.time.second) / 1.0617) / 60,
second=int((db_instance.time.minute * 60 + db_instance.time.second) / 1.0617) % 60)
Update
As suggested by Dandekar I've extended the timedelta class to include multiplication and division:
from datetime import timedelta
class TimeDeltaExtended(timedelta):
def __div__(self, divisor):
return TimeDeltaExtended(seconds=self.total_seconds()/divisor)
def __mul__(self, multiplier):
return TimeDeltaExtended(seconds=self.total_seconds()*multiplier)
Division by float does not work in Python 2.x but works in python 3.2x So normally, to SUBTRACT time, you do something like below:
dt = date+" "+time
dt=datetime.datetime.strptime(dt, "%d/%m/%Y %H:%M:%S")
delta=datetime.timedelta(seconds=1.0617)
adjusted=dt-delta
print adjusted.strftime("%d/%m/%Y %H:%M:%S")
To DIVIDE time, you would have to subclass timedelta to something like
class MyTimeDelta(timedelta):
def __div__(self, deltafloat):
# Code
More on that here. Hope that helps.