import numpy as np
from scipy.fft import fft
import matplotlib.pyplot as plt
t = np.linspace(0, 2*np.pi, 200)
f = np.sin(10*t)
F = fft(f)
freq = np.fft.fftfreq(len(t), d=t[1]-t[0])
fig, (ax1, ax2) = plt.subplots(nrows=2, figsize=(8, 6))
ax1.plot(t, f)
ax1.set_xlabel('Time [s]')
ax1.set_ylabel('Amplitude')
ax2.plot(freq, np.abs(F))
ax2.set_xlabel('Frequency [Hz]')
ax2.set_ylabel('Amplitude')
plt.show()