Source code for pm4py.algo.discovery.dfg.variants.native

from collections import Counter

from pm4py.util import constants, exec_utils
from pm4py.util import xes_constants as xes_util
from enum import Enum
from typing import Optional, Dict, Any, Union, Tuple
from pm4py.objects.log.obj import EventLog, EventStream




class Parameters(Enum):
    ACTIVITY_KEY = constants.PARAMETER_CONSTANT_ACTIVITY_KEY
    WINDOW = "window"
    KEEP_ONCE_PER_CASE = "keep_once_per_case"





def apply(
    log: Union[EventLog, EventStream],
    parameters: Optional[Dict[Union[str, Parameters], Any]] = None,
) -> Dict[Tuple[str, str], int]:
    return native(log, parameters=parameters)





def native(
    log: Union[EventLog, EventStream],
    parameters: Optional[Dict[Union[str, Parameters], Any]] = None,
) -> Dict[Tuple[str, str], int]:
    """
    Counts the number of directly follows occurrences, i.e. of the form <...a,b...>, in an event log.

    Parameters
    ----------
    log
        Trace log
    parameters
        Possible parameters passed to the algorithms:
            activity_key -> Attribute to use as activity

    Returns
    -------
    dfg
        DFG graph
    """
    if parameters is None:
        parameters = {}
    activity_key = exec_utils.get_param_value(
        Parameters.ACTIVITY_KEY, parameters, xes_util.DEFAULT_NAME_KEY
    )
    window = exec_utils.get_param_value(Parameters.WINDOW, parameters, 1)
    keep_once_per_case = exec_utils.get_param_value(
        Parameters.KEEP_ONCE_PER_CASE, parameters, False
    )
    if keep_once_per_case:
        dfgs = map(
            (
                lambda t: set(
                    (t[i - window][activity_key], t[i][activity_key])
                    for i in range(window, len(t))
                )
            ),
            log,
        )
    else:
        dfgs = map(
            (
                lambda t: [
                    (t[i - window][activity_key], t[i][activity_key])
                    for i in range(window, len(t))
                ]
            ),
            log,
        )
    return Counter([dfg for lista in dfgs for dfg in lista])