ratingslib.ratings.rating module

This module provides the RatingMethod abstract class for rating systems.

class RatingSystem(version: str)

Bases: object

This class represents a Rating method / system. The logic behind class structure is that the rating system can be divided in two phases:

• the preparation phase, preparation_phase()

• the computation phase, computation_phase()

Extend this class and override abstract methods to define a rating system.

Warning: This class should not be used directly. Use derived classes instead.

Parameters

version (str) – A string that shows the version of rating system. The available versions can be found in ratingslib.utils.enums.ratings class.

score

The score number that represents rating for a single item

Type

float

rating

The rating value of items are stored in a numpy array of shape (n,)

where n = the total number of teams

Type

numpy.ndarray

ord_dict_attr

An order dictionary that maps attributes

Type

Optional[dict]

params_key

String representation of parameters. For rating systems without parameters their version is used.

Type

str

abstract computation_phase()

To be overridden in subclasses.

abstract preparation_phase(data_df: DataFrame, items_df: DataFrame, columns_dict: Optional[Dict[str, Any]] = None)

To be overridden in subclasses.

abstract rate(data_df: DataFrame, items_df: DataFrame, sort: bool = False, columns_dict: Optional[Dict[str, Any]] = None) → DataFrame

This method computes ratings for a pairwise data. (e.g. soccer teams games). To be overridden in subclasses.

Parameters

• data_df (pandas.DataFrame) – The pairwise data.

• items_df (pandas.DataFrame) – Set of items (e.g. teams) to be rated

• sort (bool, default=True.) – If true, the output is sorted by rating value

• columns_dict (Optional[Dict[str, str]]) – The column names of data file. See ratingslib.datasets.parameters.COLUMNS_DICT for more details.

Returns

items_df – The set of items with their rating and ranking.

Return type

pandas.DataFrame

rate_from_file(filename: str, pairwise: bool = True, reverse_attributes_cols: Optional[List[str]] = None, sort: bool = False, columns_dict: Optional[Dict[str, Any]] = None) → DataFrame

This method computes ratings for a pairwise data. (e.g. soccer teams games). Data are stored in a filename.

Parameters

• filename (str) – The name of file or file path+filename.

• sort (bool, default=True) – If True, the output is sorted by rating value.

• pairwise (bool, default=True) – If True then data is in pairwise structure.

• reverse_attributes_cols (Optional[List[str]], default = None) – Name of columns (from csv file) where the numerical scoring scale runs in the opposite direction. Valid only if pairwise is False.

• columns_dict (Optional[Dict[str, str]], default=None) – The column names of data file. See ratingslib.datasets.parameters.COLUMNS_DICT for more details.

Returns

items_df – The set of items with their rating and ranking.

Return type

pandas.DataFrame

set_rating(items_df: DataFrame, rating_lower_best: bool = False, sort: bool = False) → DataFrame

Set the rating values and produce items rankings

Parameters

• items_df (pandas.DataFrame) – Set of items (e.g. teams) to be rated

• rating_lower_best (bool, default=True) – If True then lower rating is better, else False

• sort (bool, default=True) – Sort the items by rating value if True

Returns

items_df – The set of items with their rating and ranking.

Return type

pandas.DataFrame

create_ordered_dict(**kwargs)

property params_key: str