import numpy  as np
import matplotlib.pyplot as plt

x = np.linspace(0, np.pi*4, 100)
y1 = np.cos(x) + np.sin(x)
y2 = np.cos(-x) + np.sin(x*2)

fig, ax1 = plt.subplots()
ax2 = ax1.twinx()

ax1.plot(x, y1, color='orangered')
ax2.plot(x, y2, color='dodgerblue')

ax1.tick_params(axis='y', colors='orangered')
ax2.tick_params(axis='y', colors='dodgerblue')