Pyimof (for Python image optical flow) is a pure python package for dense optical flow estimation. Please visit the documentation and the gallery for more details.
pip install pyimof
Using Pyimov is as easy as
from matplotlib import pyplot as plt
import pyimof
I0, I1 = pyimof.data.hydrangea()
u, v = pyimof.solvers.tvl1(I0, I1)
pyimof.display.plot(u, v)
plt.show()
to obtain