Generate cyclic time features on pandas.DataFrame using a pandas.DateTime column

cyclical_encoder.py

from itertools import count

import pandas as pd
import numpy as np

def cyclical_encoder(data: pd.DataFrame, 
                     time_column: str, 
                     time_unit: str, 
                     normalize_val: float, 
                     label_suffix: str) -> pd.DataFrame:
    """
    Encodes a cyclical time unit using sinus and cosine
    """
    
    # Get time values
    time_values = getattr(data[time_column].dt, time_unit)
    
    sin_time = np.sin(2*np.pi*time_values / normalize_val)
    cos_time = np.cos(2*np.pi*time_values / normalize_val)
    
    # Determine labels, check if already exists
    sin_label = 'sin_{}_'.format(time_unit)
    cos_label = 'cos_{}_'.format(time_unit)
    if label_suffix:
        sin_label += str(label_suffix)
        cos_label += str(label_suffix)
    else:
        for n in count():
            if not sin_label + str(n) in data.columns:
                break
        sin_label += str(n)
        cos_label += str(n)
    
    return pd.concat([data, pd.DataFrame(columns=[cos_label, sin_label], data=np.array([cos_time, sin_time]).T)], axis=1)