I know how to cycle through a list of colors in matplotlib. But is it possible to do something similar with line styles (plain, dotted, dashed, etc.)? I'd need to do that so my graphs would be easier to read when printed. Any suggestions how to do that?

Something like this might do the trick:

import matplotlib.pyplot as plt
from itertools import cycle
lines = ["-","--","-.",":"]
linecycler = cycle(lines)
plt.figure()
for i in range(10):
    x = range(i,i+10)
    plt.plot(range(10),x,next(linecycler))
plt.show()

Result:

Edit for newer version (v2.22)

import matplotlib.pyplot as plt
from cycler import cycler
#
plt.figure()
for i in range(5):
    x = range(i,i+5)
    linestyle_cycler = cycler('linestyle',['-','--',':','-.'])
    plt.rc('axes', prop_cycle=linestyle_cycler)
    plt.plot(range(5),x)
    plt.legend(['first','second','third','fourth','fifth'], loc='upper left', fancybox=True, shadow=True)
plt.show()

For more detailed information consult the matplotlib tutorial on "Styling with cycler"
To see the output click "show figure"