import matplotlib.pyplot as plt
import numpy as np
%matplotlib inline

# create some random data
x = np.cumsum(np.random.rand(1000)-0.5)

# plot it
fig, ax = plt.subplots(1,1,figsize=(10,3))
plt.plot(x, color='k')
plt.plot(len(x)-1, x[-1], color='r', marker='o')

# remove all the axes
for k,v in ax.spines.items():
    v.set_visible(False)
ax.set_xticks([])
ax.set_yticks([])

#show it
plt.show()