How to convert time domain data into frequency domain data using python

Question

I have a dataframe named dataTime with 4335 rows with 20 secondes between every two rows.

dataTime.shape
Out[630]: (4335,)

enter image description here

I want to plot my data into frequency domain

from scipy.fftpack import fft
import matplotlib.pyplot as plt

dataT = dataTime.values
xf=fft(dataT)
freq = geek.fft.fftfreq(len(dataT))
plt.plot(freq,xf)

enter image description here

I'm not sure if it's the result that should be or not and how to interpret the plot in the frequency domain