I have a simple line plot and need to move the y-axis ticks from the (default) left side of the plot to the right side. Any thoughts on how to do this?

Use ax.yaxis.tick_right()

for example:

from matplotlib import pyplot as plt

f = plt.figure()
ax = f.add_subplot(111)
ax.yaxis.tick_right()
plt.plot([2,3,4,5])
plt.show()

enter image description here

For right labels use ax.yaxis.set_label_position("right"), i.e.:

f = plt.figure()
ax = f.add_subplot(111)
ax.yaxis.tick_right()
ax.yaxis.set_label_position("right")
plt.plot([2,3,4,5])
ax.set_xlabel("$x$ /mm")
ax.set_ylabel("$y$ /mm")
plt.show()

joaquin’s answer works, but has the side effect of removing ticks from the left side of the axes. To fix this, follow up tick_right() with a call to set_ticks_position('both'). A revised example:

from matplotlib import pyplot as plt

f = plt.figure()
ax = f.add_subplot(111)
ax.yaxis.tick_right()
ax.yaxis.set_ticks_position('both')
plt.plot([2,3,4,5])
plt.show()

The result is a plot with ticks on both sides, but tick labels on the right.

enter image description here

Just is case somebody asks (like I did), this is also possible when one uses subplot2grid. For example:

import matplotlib.pyplot as plt
plt.subplot2grid((3,2), (0,1), rowspan=3)
plt.plot([2,3,4,5])
plt.tick_params(axis="y", which="both", labelleft="off", labelright="on")
plt.show()

It will show this:

enter image description here