def _do_add(self, time, value):
assert value > 0, "Value must be greater than 0"
if (self.unit == self._generic_unit
and not isinstance(time, (pd.Timestamp, datetime))):
return time + value
elif self.unit not in [self._Observations]:
return add_td(time, value, self.unit)
assert self.data is not None, "Must call timedelta with data"
all_times = self.data[self.data > time].tolist()
if self.unit == self._Observations:
if len(all_times) < value:
raise NotEnoughData()
return all_times[value - 1]
raise Exception("Invalid unit")
def _do_sub(self, time, value):
assert value > 0, "Value must be greater than 0"
if (self.unit == self._generic_unit
and not isinstance(time, (pd.Timestamp, datetime))):
return time - value
elif self.unit != self._Observations:
return add_td(time, -1 * value, self.unit)
assert self.data is not None, "Must call timedelta with data"
# reverse because we want to count backwards when we subtract
if self.inclusive:
all_times = self.data[self.data <= time].tolist()[::-1]
else:
all_times = self.data[self.data < time].tolist()[::-1]
if self.unit == self._Observations:
if len(all_times) < value:
raise NotEnoughData()
return all_times[value - 1]
raise Exception("Invalid unit")