$\rho$ in text for plots erroring

[lheagy]

It looks like the symbol $\rho$ is not being recognized

import numpy as np
import matplotlib.pyplot as plt

# this works
plt.plot(np.random.rand(5))
plt.title('$\sigma$')
plt.show()

# this errors 
plt.plot(np.random.rand(5))
plt.title('$\rho$')
plt.show()

mpl_rho_err.txt

[jenshnielsen]

The problem is that \r is a control character in python. Try doing the following in a python shell and you will see what happens:

>>> a = '$\rho$'
>>> print(a)
ho$

The solution is to either escape the \ or use a raw string

>>> a = '$\\rho$'
>>> print(a)
$\rho$
>>> a = r'$\rho$'
>>> print(a)
$\rho$