code: def fft_feat(df, cols):
      for col in cols:
          fft_df = np.fft.fft(np.asarray(df[col].tolist()))
          fft_df = pd.DataFrame({"fft": fft_df})
          df[col + "_FFTABS"] = (
              fft_df["fft"].apply(lambda x: np.abs(x)).values
          )
          df[col + "_FFTANGLE"] = (
              fft_df["fft"].apply(lambda x: np.angle(x)).values
          )
      return df
  
imports: import pandas
  import numpy
  import statsmodels.api
  from scipy import signal, integrate
  from pykalman import UnscentedKalmanFilter
  from tsaug import *
  from fbprophet import Prophet
  import pylab
  from seasonal.periodogram import periodogram
label_desc: Use image node_id 18 for calling a global function with example usage: fft_feat(df, cols) and returns: df