Agate compute method to generate streaks of consecutive values in a dataset. WIP

streaks.py

import agate

class Streaks(agate.Computation):
    """
    Computes the streaks of consecutive values in a column.
    Each streak will be given an increasing
    integer value so that you can group by this later to
    find longest consecutive streak.
    """

    def __init__(self, column_name):
        self._column_name = column_name

    def get_computed_data_type(self, table):
        """
        The return value is a numerical average.
        """
        return agate.Number()

    def run(self, table):
        new_column = []
        streak = 0

        for i, row in enumerate(table.rows):
            if i > 0:
                if row[self._column_name] != table.rows[i - 1][self._column_name]:
                    streak = streak + 1

            new_column.append(streak)

        return new_column