import matplotlib.pyplot as plt
from scipy.interpolate import UnivariateSpline
x = np.linspace(-3, 3, 50)
y = np.exp(-x**2) + 0.1 * np.random.randn(50)
plt.plot(x, y, 'ro', ms=5)

# Use the default value for the smoothing parameter:

spl = UnivariateSpline(x, y)
xs = np.linspace(-3, 3, 1000)
plt.plot(xs, spl(xs), 'g', lw=3)

# Manually change the amount of smoothing:

spl.set_smoothing_factor(0.5)
plt.plot(xs, spl(xs), 'b', lw=3)
plt.show()