"""
"""
from chainladder.core.base import TriangleBase


class Triangle(TriangleBase):
    """
    The core data structure of the chainladder package

    Parameters
    ----------
    data : DataFrame
        A single dataframe that contains columns represeting all other
        arguments to the Triangle constructor
    origin : str or list
         A representation of the accident, reporting or more generally the
         origin period of the triangle that will map to the Origin dimension
    development : str or list
        A representation of the development/valuation periods of the triangle
        that will map to the Development dimension
    columns : str or list
        A representation of the numeric data of the triangle that will map to
        the columns dimension.  If None, then a single 'Total' key will be
        generated.
    index : str or list or None
        A representation of the index of the triangle that will map to the
        index dimension.  If None, then a single 'Total' key will be generated.

    Attributes
    ----------
    index : Series
        Represents all available levels of the index dimension.
    columns : Series
        Represents all available levels of the value dimension.
    origin : DatetimeIndex
        Represents all available levels of the origin dimension.
    development : Series
        Represents all available levels of the development dimension.
    valuation : DatetimeIndex
        Represents all valuation dates of each cell in the Triangle.
    shape : tuple
        The 4D shape of the triangle instance
    link_ratio, age_to_age
        Displays age-to-age ratios for the triangle.
    valuation_date : date
        The latest valuation date of the data
    loc : Triangle
        pandas-style ``loc`` accessor
    iloc : Triangle
        pandas-style ``iloc`` accessor
    latest_diagonal : Triangle
        The latest diagonal of the triangle
    values : array
        4D numpy array underlying the Triangle instance
    T : Triangle
        Transpose index and columns of object.  Only available when Triangle is
        convertible to DataFrame.
    """
    pass
