# Source code for pm4py.ml

```
'''
This file is part of PM4Py (More Info: https://pm4py.fit.fraunhofer.de).
PM4Py is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
PM4Py is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with PM4Py. If not, see <https://www.gnu.org/licenses/>.
'''
from typing import Union, Tuple
import pandas as pd
from pm4py.objects.log.obj import EventLog, EventStream
from pm4py.util import constants
import random
[docs]def split_train_test(log: Union[EventLog, pd.DataFrame], train_percentage: float = 0.8) -> Union[
Tuple[EventLog, EventLog], Tuple[pd.DataFrame, pd.DataFrame]]:
"""
Split an event log in a training log and a test log (for machine learning purposes)
Parameters
--------------
log
Event log / Pandas dataframe
train_percentage
Fraction of traces to be included in the training log (from 0.0 to 1.0)
Returns
--------------
training_log
Training event log
test_log
Test event log
"""
if type(log) not in [pd.DataFrame, EventLog, EventStream]: raise Exception("the method can be applied only to a traditional event log!")
if type(log) is pd.DataFrame:
cases = set(log[constants.CASE_CONCEPT_NAME].unique())
train_cases = set()
test_cases = set()
for c in cases:
r = random.random()
if r <= train_percentage:
train_cases.add(c)
else:
test_cases.add(c)
train_df = log[log[constants.CASE_CONCEPT_NAME].isin(train_cases)]
test_df = log[log[constants.CASE_CONCEPT_NAME].isin(test_cases)]
return train_df, test_df
else:
from pm4py.objects.log.util import split_train_test
return split_train_test.split(log, train_percentage=train_percentage)
[docs]def get_prefixes_from_log(log: Union[EventLog, pd.DataFrame], length: int) -> Union[EventLog, pd.DataFrame]:
"""
Gets the prefixes of a log of a given length
Parameters
----------------
log
Event log / Pandas dataframe
length
Length
Returns
----------------
prefix_log
Log contain the prefixes:
- if a trace has lower or identical length, it is included as-is
- if a trace has greater length, it is cut
"""
if type(log) not in [pd.DataFrame, EventLog, EventStream]: raise Exception("the method can be applied only to a traditional event log!")
if type(log) is pd.DataFrame:
from pm4py.util import pandas_utils
log = pandas_utils.insert_ev_in_tr_index(log)
return log[log[constants.DEFAULT_INDEX_IN_TRACE_KEY] <= (length-1)]
else:
from pm4py.objects.log.util import get_prefixes
return get_prefixes.get_prefixes_from_log(log, length)
```