Source code for featuretools.primitives.standard.aggregation.max_consecutive_zeros

from woodwork.column_schema import ColumnSchema
from woodwork.logical_types import Double, Integer

from featuretools.primitives.base import AggregationPrimitive

[docs]class MaxConsecutiveZeros(AggregationPrimitive): """Determines the maximum number of consecutive zero values in the input Args: skipna (bool): Ignore any `NaN` values in the input. Default is True. Examples: >>> max_consecutive_zeros = MaxConsecutiveZeros() >>> max_consecutive_zeros([1.0, -1.4, 0, 0.0, 0, -4.3]) 3 `NaN` values can be ignored with the `skipna` parameter >>> max_consecutive_zeros_skipna = MaxConsecutiveZeros(skipna=False) >>> max_consecutive_zeros_skipna([1.0, -1.4, 0, None, 0.0, -4.3]) 1 """ name = "max_consecutive_zeros" input_types = [ [ColumnSchema(logical_type=Integer)], [ColumnSchema(logical_type=Double)], ] return_type = ColumnSchema(logical_type=Integer, semantic_tags={"numeric"}) stack_on_self = False default_value = 0
[docs] def __init__(self, skipna=True): self.skipna = skipna
def get_function(self): def max_consecutive_zeros(x): if self.skipna: x = x.dropna() # convert the numeric values to booleans for processing x[x.notnull()] = x[x.notnull()].eq(0) # find the locations where the value changes from the previous value not_equal = x != x.shift() # Use cumulative sum to determine where consecutive values occur. When the # sum changes, consecutive non-zero values are present, when the cumulative # sum remains unchnaged, consecutive zero values are present. not_equal_sum = not_equal.cumsum() # group the input by the cumulative sum values and use cumulative count # to count the number of consecutive values. Add 1 to account for the cumulative # sum starting at zero where the first zero occurs consecutive = x.groupby(not_equal_sum).cumcount() + 1 # multiply by the boolean input to keep only the counts that correspond to # zero values consecutive_zero = consecutive * x # return the max of all the consecutive zero values return consecutive_zero.max() return max_consecutive_zeros