from woodwork.column_schema import ColumnSchema
from woodwork.logical_types import Datetime, Double
from featuretools.primitives.base.aggregation_primitive_base import AggregationPrimitive
from featuretools.utils import convert_time_units
[docs]class TimeSinceFirst(AggregationPrimitive):
"""Calculates the time elapsed since the first datetime (in seconds).
Description:
Given a list of datetimes, calculate the
time elapsed since the first datetime (in
seconds). Uses the instance's cutoff time.
Args:
unit (str): Defines the unit of time to count from.
Defaults to seconds. Acceptable values:
years, months, days, hours, minutes, seconds, milliseconds, nanoseconds
Examples:
>>> from datetime import datetime
>>> time_since_first = TimeSinceFirst()
>>> cutoff_time = datetime(2010, 1, 1, 12, 0, 0)
>>> times = [datetime(2010, 1, 1, 11, 45, 0),
... datetime(2010, 1, 1, 11, 55, 15),
... datetime(2010, 1, 1, 11, 57, 30)]
>>> time_since_first(times, time=cutoff_time)
900.0
>>> from datetime import datetime
>>> time_since_first = TimeSinceFirst(unit = "minutes")
>>> cutoff_time = datetime(2010, 1, 1, 12, 0, 0)
>>> times = [datetime(2010, 1, 1, 11, 45, 0),
... datetime(2010, 1, 1, 11, 55, 15),
... datetime(2010, 1, 1, 11, 57, 30)]
>>> time_since_first(times, time=cutoff_time)
15.0
"""
name = "time_since_first"
input_types = [ColumnSchema(logical_type=Datetime, semantic_tags={"time_index"})]
return_type = ColumnSchema(logical_type=Double, semantic_tags={"numeric"})
uses_calc_time = True
description_template = "the time since the first {}"
[docs] def __init__(self, unit="seconds"):
self.unit = unit.lower()
def get_function(self):
def time_since_first(values, time=None):
time_since = time - values.iloc[0]
return convert_time_units(time_since.total_seconds(), self.unit)
return time_since_first